ERROL Gulden's long-term injury absence from Sydney has the potential to not only derail the Swans' season but change the premiership race altogether.

We need to look back only 12 months to understand the value Gulden brings to his team, with the Swans managing a complete turnaround in 2025 when the midfielder returned from ankle surgery in the middle of the season.

Sydney won just five of its 13 games without Gulden last year, then went on a run of seven wins from 10 games once he came back to be one of the competition's form teams.

There were other factors at play – the likes of Tom Papley, Callum Mills and Logan McDonald were also injured, Justin McInerney, Joel Amartey and Lewis Melican were banned for at least three games each and Dean Cox was in his coaching infancy – but the improvement upon Gulden's return was dramatic.

Statistics provided by Champion Data show the two-time All-Australian's inclusion improved his team across the board.

The clearance differential went from 13th in the competition to fourth, contested possession differential from 13th to second and uncontested differential from 14th to fourth.

And moving the ball from defensive 50 to forward 50 went from ninth to second.

In short, Sydney won the ball better and moved it more efficiently when Gulden played and the wins followed.

How will they go this season without their dynamic left-footer?

JORDAN DAWSON

The Crows have an issue with midfield depth, making captain Dawson an obvious candidate as the club's most important player. His size, skill, leadership and versatility make him an impossible player to replace – particularly with Dan Curtin sidelined – and his ability to stand up in big moments and play a match-winning role is vital for the Crows. Izak Rankine is also a clear candidate, but the Crows showed they can win without him in round one. The less obvious option is half-back Wayne Milera. Speed and skill across half-back is an important ingredient for clubs in 2026, particularly with the tightening of the stand rule, and the Crows are leaning heavily on Milera to provide those traits. He made a brilliant start to the season in round one with 34 disposals and a team-high 673m gained and looks primed for a big year. – Nathan Schmook

HARRIS ANDREWS

Such an even team with threats across each line, the Lions can least afford to be without co-captain Andrews. Not only is he arguably the best key defender in the competition, and one of the best of his generation, Andrews is a calming and directing voice in the back half of the ground. A healthy list would have Jack Payne and Darcy Gardiner as possible replacements in his absence, but no one has the reach and defensive nous to match the game's elite forwards like Andrews. – Michael Whiting

JACOB WEITERING

Weitering is undoubtedly one of Carlton's most reliable, no-fuss and high quality players. But, alongside that, his value to the side is also underscored by the club's lack of quality and experienced key defenders alongside him. Weitering has proved his credentials with two best and fairests, as well as an All-Australian blazer, doing it in one of the toughest positions to play on the field. Across the last couple of seasons, he's flourished in that role while mentoring a couple of high-potential youngsters next to him in Harry O'Farrell and Harry Dean as well. - Riley Beveridge

NICK DAICOS

At 23, Nick Daicos has 109 Brownlow votes to his name, including 32 and 38 in the past two seasons. His first 97 games have been outrageously good and not many players in the competition can influence games like this son of a gun. Collingwood's midfield doesn't bat as deep as it did when it won the flag in 2023, so without him, Craig McRae's side would be in a lot of trouble. Josh Gabelich

ZACH MERRETT

Central to Essendon's decision to keep Merrett in last year's trade period was the fact that he remains the Bombers' best player. The reality is the Bombers' improvement will be judged when this question is harder to answer – and that time is coming as Sam Durham develops into an emerging gun of the competition. Nic Martin would also be right up there as the Bombers' most important player given his creativity and versatility, but he is out for the season after further knee surgery late last year. The next wave of Bombers has strong talent and Nate Caddy, Isaac Kako and Zach Reid are foundation players to build around but at this stage the six-time best and fairest in Merrett remains the Bombers' chief deliverer of the ball by foot and their most important player. - Cal Twomey

JOSH TREACY

Whether he's marking the ball deep, working up the ground as a link-up player, or crashing packs to create opportunities for small forwards, key forward Josh Treacy is crucial to how the Dockers score. As the club's leading goalkicker last season with 44, Treacy was still able to impact matches when the goals weren't flowing, showing he is one of the club's best kicks inside 50. He can also push into defence at the right times and has taken match-saving marks on multiple occasions. A leader at 23 and a candidate to captain Freo in the future, he is signed up until the end of 2030. The Dockers' midfield is full of stars, meaning the absence of one can be covered, while Alex Pearce is a vital player in defence. Luke Jackson's versatility as a ruckman and midfielder makes him a supremely important player in 2026. – Nathan Schmook

TOM ATKINS

Chris Scott has made versatility a priority during his 16 seasons at the helm, which means the Cats are often able to fill a void with a capable replacement. Perhaps the one role they might find hardest to cover is Atkins' work as a defensive midfielder. It's Atkins' pressure, discipline and toughness around stoppage that allows running weapons Max Holmes and Bailey Smith to be deployed to full effect. Atkins has produced four of the eight most prolific tackling seasons in Geelong history, including his incredible 2025 campaign in which he averaged 8.9 tackles a game – the most in recorded VFL/AFL history. Combine Atkins' tenacity with his ball-winning – he averaged a career-best 20.5 disposals a game last year – and it's clear to see why he's so valued at Geelong. – Michael Rogers

SAM COLLINS

There's a couple of options here, but we're going with Collins. The man that went back through the VFL to get a second chance in the AFL has turned himself into one of the most reliable defenders in the League. Collins can wrestle with anyone, has the speed to match most on the lead and is as competitive as they come. The Suns have other key defenders that could do the job on paper – Mac Andrew, Charlie Ballard and Oscar Adams – but the combination of presence and voice makes Collins a difficult man to replace. – Michael Whiting

TOBY GREENE

Greene gives Greater Western Sydney an identity like few others. His hard-edged, ruthless style makes him an inspirational captain that his Giants teammates rally around. He's also a straight-up superstar. Having claimed three All-Australian blazers and two best and fairests playing predominantly as a forward across his career, coach Adam Kingsley tabbed Greene to spend more time in the midfield this season given the absence of Tom Green and Josh Kelly among others. He responded with 20 and 26 disposals in his first two games for the year, showing his worth in multiple positions. - Riley Beveridge

TOM BARRASS

The class and poise of Will Day has been noticeably absent in Hawthorn's midfield after copping a pasting or two over the last year or so. But the player the team can ill-afford to lose is Barrass. Thankfully for the Hawks, the 30-year-old hasn't missed a beat since crossing from West Coast, playing 25 of 26 games in his first year at the club on the way to a preliminary final. During his 10 years at the Eagles, Barrass never played more than 19 games a season. In 2025, he was ranked 16th in contested marks and 12th in intercepts in the AFL, and although he's not overly quick, Barrass is among the best key defenders in the competition and is a nightmare match-up for the opposition's most dangerous forwards. - Brandon Cohen

MAX GAWN

You'd be hard pressed to find a more important figure at a club than what Gawn is to Melbourne. At 34, the Demons captain continues to prove age is just a number as shown by his colossal effort on Sunday when he ran Tom De Koning ragged. Gawn's dominance doesn't end at stoppage, with his work around the ground equally elite. A now record-equal eight-time All-Australian, Gawn finished last season averaging career-highs for disposals (20.7), marks (5.7) and clearances (5.3), ranked second in the League for contested marks and added a third club champion award to his long list of achievements. Stats aside, his leadership is equally important with his direction and guidance around Melbourne's young, rebuilding group vital to the Demons' development. - Alison O'Connor

HARRY SHEEZEL

Sheezel has become the face of North Melbourne's future. The former No.3 draft pick remarkably won a best and fairest in his maiden AFL season. He made the All-Australian squad in his second season, then claimed another best and fairest in his third. Who knows what the fourth will bring? That's been the impact of a player who was billed to start his career as a forward, but instead spent it playing mainly across half-back and has since moved into the midfield. Still just 21 years of age, Sheezel is the type of A-grade talent that North Melbourne hopes will lift it back towards the top. - Riley Beveridge

ZAK BUTTERS

There can be only one answer here and that's Butters. Ranked No.4 in AFL.com.au's The 25, Butters is physically and emotionally the heartbeat of the team. He not only wins the ball as well as any midfielder in the competition but can spread from the contest and use it skilfully on the outside. It's a combination of abilities only a handful of players possess. Despite his combative nature, Butters has been quite durable in his eight seasons and for Port to make progress in 2026, he'll need to continue to be. – Michael Whiting

TOM LYNCH

Since the retirement of Jack Riewoldt at the end of 2023, Richmond has had just one answer to this question. Lynch's presence in the Tigers' forward line can't be replaced by anyone on their list, and at the age of 33, he still commands two opponents every time the ball goes into attack. His supporting cast are either in their second year of AFL (Jonty Faull, Harry Armstrong, Tom Sims), former rugby league players (Mykelti Lefau) or smalls. Lynch's set shots may miss the mark, he will continue to retaliate to niggle and give away free kicks, but he also continues to attack the footy time and time again, taking the heat for his young forward line and directing traffic. - Sarah Black

NASIAH WANGANEEN-MILERA

Do we even need to say it … Wanganeen-Milera. From the way he reads the game to his elite skills, no one can do what he does, best exemplified by his much-vaunted game in round 20, 2025. The Saints stumped up big cash to keep the South Australian at the club for another two years, a show of just how highly they - and the rest of the football world - rate him. Not only is he integral to any success the Saints may have in the future, but the prospect of playing alongside him has been a major drawcard when recruiting players to the club. - Sophie Welsh

ERROL GULDEN

As shown above, it has to be Errol. The Swans were undermanned across the board in 2025, but their smooth-moving, sharp-kicking dual All-Australian was the biggest loss of all. And covering for Gulden this year will be a different challenge to last given he's taken on a more inside role in the two games so far in 2026 (he's had tackle counts of 11 and eight compared to his career average of 3.9 per game). The 23-year-old should again be back again for the run to the finals, but it's a big watch on how strong a position his club will be in by that point of the season. - Martin Smith

HARLEY REID

For the Eagles to compete with a young team, they need to hold up in the midfield much better than they did in 2025, making Reid – their best midfielder – their most important player. Winning stoppages and gaining field position makes the game more manageable for a developing team, and Reid was the Eagles' best clearance player last season (3.9 a game), even if he was left disappointed by his output. With a bigger engine and hardened body in his third season, the No.1 pick is expected to elevate his game in 2026. Young star Reuben Ginbey and gun recruit Brandon Startcevich will be important in defence, while All-Australian key forward Jake Waterman holds the keys in attack alongside impressive youngster Jobe Shanahan. Captain Liam Baker sets standards on field and leads a young group superbly. – Nathan Schmook   

SAM DARCY

Luke Beveridge's midfield is stacked and built around one of the most brilliant midfielders of this century in Marcus Bontempelli, but Sam Darcy is a point of difference no one else has. At 208cm, Darcy's reach is unstoppable and his foot skills stand out. After kicking 48 goals last year around a knee injury that wiped him out mid-year, the 22-year-old is a formidable force that is only getting to get better. - Josh Gabelich