ESSENDON faces a rejig of its backline ahead of Thursday night's elimination final with West Coast, with defender Martin Gleeson to miss with a calf injury.

Gleeson did not take part in Monday's training session at Tullamarine, instead watching from the sidelines with a compression sock on his left calf. has confirmed he will miss this week's trip to Perth to tackle the Eagles with the minor injury, but will be aiming to be available for the following week if the Bombers progress to a semi-final.

Gleeson at Essendon training on Monday last week. 

The Bombers held over half-back Jordan Ridley from playing in the VFL on the weekend and he could come in to replace Gleeson against the Eagles. Ridley trained with the main group on Monday and has played six senior games this season. 

It is a blow for Gleeson, who has been important for the Bombers since breaking back into the line-up in round 15.

The attacking and intercepting half-back has played every game since then, having overcome a serious ankle fracture and dislocated heel in the pre-season JLT Community Series in 2018 that saw him miss all of last year. 

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Small backman Ben McNiece has also been used as a relief defender, having made five senior appearances this season.

It is not the injury news Essendon wanted, particularly as it looks to bring back four key players for its knockout clash with last year's premiers.

Dyson Heppell (foot), Cale Hooker (illness), Orazio Fantasia (hip) and Jake Stringer (soreness) all missed the round 23 loss to Collingwood but all trained on Monday and are set to return.

Orazio Fantasia (second from left) is likely to return to face West Coast

Dual All Australian Michael Hurley also looks likely to play through pain after his shoulder injury against the Magpies. 

Hurley, who partially dislocated his right shoulder, took part in Monday's session, including contested marking drills. 

He will require surgery at the end of Essendon's season, but the Bombers believe he is most likely to meet the Eagles.

Meanwhile, defender Matt Dea has announced he will retire at the end of Essendon's season. 

Dea, 27, played 39 games for Essendon and 31 for Richmond for a career total of 70 across 10 seasons.

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He was originally drafted by Richmond with pick No.44 in the 2009 NAB AFL Draft and was delisted at the end of 2015, before joining the Bombers for 2016 under the top-up concessions afforded the club after 12 of its players were banned for anti-doping violations. 

Dea was re-drafted at the end of the 2016 season and played out three more years.