SYDNEY defender Harry Cunningham is in doubt for Friday's preliminary final against Fremantle after suffering a calf injury at training on Wednesday, while forward Joel Amartey has officially been ruled out but midfielder Justin McInerney will make his long-awaited return.

Swans coach Dean Cox said the club was waiting on a medical assessment after Cunningham experienced a calf issue at training on Wednesday before making a call on the veteran.

The 32-year-old was one of the Swans' best players in their 53-point qualifying final victory over Brisbane. After playing 12 games during the home and away season, Cunningham returned to the team in round 23 when the club was forced to make multiple changes following five club-imposed suspensions.

"At the minute, we're just waiting on Harry Cunningham to see how he pulls up today," he said.

"We'll get through today, have a bit of a discussion about what the best team looks like, and go from there."

Amartey, who missed selection for the qualifying final despite passing key fitness benchmarks in his return from an Achilles injury, was also pushing for a recall. However, Hayden McLean proved too hard to shift from Sydney's forward setup.

In the qualifying final, key forward Logan McDonald kicked a career-high six goals, Charlie Curnow chipped in with five, and McLean kicked three. Earlier in the season, Curnow and McLean spearheaded the attack against Fremantle in the round 18 loss while Amartey and McDonald were sidelined.

"Our forward line setup functioned quite well in the first qualifying final against Brisbane," he said. 

"We also need to acknowledge that the players who played in that forward line group, whether they were tall or small, played their role as well as we needed them to. So, the decision was, 'Do we have to turn that around and change it, or do we just go in with what worked?' And that's what we're going to do."

Cox highlighted how tough it is to drop players for a preliminary final, stressing the importance of delivering the news with respect and clear tactical explanations.

"All conversations are tough when you tell players they aren't playing in a prelim final," he said.

"It's something you have to do, and you do it as respectfully as possible, but you also talk through the process of why we made the decision."

McInerney will make his long-awaited return from a hamstring injury for the do-or-die clash, ending a 15-week absence.

The 26-year-old is the likely the replacement for injured captain Callum Mills in the midfield after returning to team training last week. The 26-year-old suffered a severe hamstring injury against St Kilda in round 13.

"Justin has had a lot of work put in throughout this period of time, and it's a matter of now backing him in," Cox said. 

"I just want him to do what's required of him. It's not about putting the team on his shoulders, but doing what's needed at the right time. We've spoken about that for the last couple of weeks with Justin ... We're excited to see him back in the team."

Speaking to AFL.com.au, McInerney said he is feeling good and eager to make his return. Despite some early-week nerves, he said he feels well prepared after completing significant rehab work with the club.

McInerney noted he would have been available for a semi-final last week had the Swans lost their opener, but was grateful for the extra rest provided by the qualifying final victory. Ahead of his return, he aims to bring composure, leadership, and drive to the lineup.

"I've done a body of work at the club, and what will be, will be," he said.

"I'm pretty keen to go out there and play my role for the team and hopefully contribute in some way.

"I want to bring a nice calm head out there with the boys, a bit of leadership, and some energy that goes a long way to getting the job done."

With Fremantle fielding three talls, key defender Lewis Melican remains in contention for selection.

"That's what we'll talk about now," Cox said.

"Obviously, things fell pretty quickly last night, and it's an opportunity where Lewis has played some footy and shown form, so expect his name to be right in the mix."

Meanwhile, Cox is yet to determine whether Mills will assist from the bench or the coaches' box after undergoing surgery on Wednesday. Having visited him following the procedure, Cox said Mills' role is still being finalised, although the skipper's focus remains on supporting the team.

"One thing Callum's always done is put the team first, and he'll do that again to support us in any way possible," he said. 

"I'm open to either of those."