Essendon midfielder Dylan Shiel will miss close to four months of football as he works his way back from a torn meniscus.

The 28-year-old is unlikely to be available for 16 weeks after he elected to repair his damaged knee, a decision which will provide better long-term meniscal integrity, but will ultimately cost the classy ball user most of the home and away season.

The 174-gamer suffered the torn meniscus in the third quarter of Essendon’s round two clash with Port Adelaide and discovered the extent of the injury following an arthroscopic procedure carried out last week.

Head of high performance Sean Murphy said the Bombers were disappointed to lose Shiel for an extended period of time.

“Dyl’ (Dylan Shiel) saw the surgeon early last week,” Murphy told Dons Digitals’ Performance Update.

“The decision was made to go in for surgery for last Tuesday. In the end, the meniscal tear was quite significant, and the decision was made to repair the meniscal tear.

“What that means now is that there’s more of a lengthy period in terms of his rehab process and it’s looking like commonly a 16-week layoff to return to play.

“It’s big chunk of footy ‘Dyl’ is going to miss this year which is unfortunate for the club and for ‘Dyl’.”

Defender Mason Redman is uncertain to play in the Dons’ Thursday night clash with Sydney after being medically subbed against St Kilda at half-time with hamstring awareness.

Murphy said Redman will be carefully managed this week to give the 23-year-old every chance to prove his fitness.

“Mason had a little bit of hamstring awareness throughout the game,” he said.

“Going into half-time, there was a bit of awareness that it could be a strain, so we just took the precaution to take him early out of the game.

“He’s had an MRI and that’s come back clear. He has some high-grade overload, so we’ll just have to manage him across the week.

“He’ll test his fitness over the next couple of days, but he’s still a chance to be available to play.”

Captain Dyson Heppell seems a likely chance to return to Essendon’s best 22 after "turning a corner" in his recovery from back spasms.

Heppell completed individual training over the Easter weekend and was a key presence during the Bombers’ main session today.

“Dyson has really turned a corner,” Murphy said.

“He did a couple of training sessions over the weekend.

“He trained fully today and if all things are going really well and he ticks of this session really well, he’ll be available to play this week.”

Murphy highlighted performances from first-game players Archie Perkins and Alec Waterman, while also giving updates on Patrick Ambrose, James Stewart and David Zaharakis.

Watch round four's performance update below.