MELBOURNE will have a series of defensive decisions to make ahead of Friday night's preliminary final against Geelong, with Joel Smith set to undergo scans on Wednesday to determine the severity of a hamstring injury sustained this week.

Smith had been parachuted into Melbourne's team as a late inclusion ahead of a round 22 victory over Adelaide, but performed strongly in his first appearance of the year and held his place heading into the club's finals series.

However, after dealing with calf and knee injuries earlier this season, the 191cm defender hurt his hamstring at training on Tuesday and will undergo scans in Western Australia on Wednesday morning to discover the extent of the blow.

The injury is almost certain to sideline Smith for the side's preliminary final on Friday night, though the club remains apprehensive to rule the 25-year-old out of any potential Grand Final should the Demons progress.

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Veteran defender Michael Hibberd had been the man competing with Smith for a place in Melbourne's side and appears his likely replacement this weekend, with speedster Jayden Hunt also available following ankle surgery.

Michael Hibberd and Demons coach Simon Goodwin during a Melbourne training session at Gosch's Paddock on August 23, 2021. Picture: Getty Images

The club's first-round pick from last year, Jake Bowey, has deputised capably in Hunt's absence over the last five matches, leaving coach Simon Goodwin with a decision to make as to which player starts the club's first preliminary final since 2018.

Adding to the conundrum for the Demons is the fact the Cats appear likely to retain a taller forward set-up for the Optus Stadium clash, with Esava Ratugolea set to hold his place alongside Tom Hawkins, Jeremy Cameron and Gary Rohan in the team's attack.

Ratugolea had just five touches upon returning to the side for last week's semi-final victory over Greater Western Sydney, but also aided Rhys Stanley in the ruck and contributed to a four-prong tall forward line that kicked 10 goals collectively.

Melbourne is still considering whether veteran Nathan Jones will return for the preliminary final, perhaps as the medical substitute, with Tom Sparrow likely to hold his place over James Jordon following a strong qualifying final performance against Brisbane.

Important forward Alex Neal-Bullen is fit and will play against Geelong on Friday night, despite minor concerns around a corked calf sustained during match simulation drills last week.