Essendon have suffered a massive AFL injury blow with gun midfielder Dylan Shiel to have knee surgery that will rule him out for four months.
Shiel tore the meniscus in his left knee in the Bombers' round-two loss to Port Adelaide and after an arthroscope found extensive damage, made the decision to have surgery to repair it.
"Dyl' (Dylan Shiel) saw the surgeon early last week," Essendon head of high performance Sean Murphy told the club's website.
"The decision was made to go in for surgery for Tuesday of last week. In the end, the meniscal tear was quite significant and the decision was made to actually 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 lay-off to return to play.
"It's big chunk of footy 'Dyl' is going to miss this year which is unfortunate for the club but also for 'Dyl'."
The Bombers said while the surgery would rule Shiel out of the majority of the home-and-away season, it would provide "long-term meniscal integrity."
Shiel's injury will provide further midfield opportunity for Darcy Parish, who starred against St Kilda, while Essendon are set to regain captain Dyson Heppell for their AFL clash with Sydney at the SCG.
Heppell was a late withdrawal ahead of the Bombers' round-two loss to Port Adelaide with a back spasm and also missed Saturday's big win over St Kilda.
"Yeah he is (available). So he's been improving all the time, he'll train today and if he gets through that fine, he'll be available for selection," coach Ben Rutten told reporters on Tuesday.
"If he plays, he'll play AFL."
Heppell could be a straight swap for dashing defender Mason Redman, who was substituted off against St Kilda with hamstring tightness.
Rutten said Redman avoided a hamstring tear but Essendon would see how he pulled up.
Essendon face a stern task against Sydney, who are 3-0 and coming off a brilliant win over reigning premiers Richmond.
The Bombers will plan for Sydney superstar Lance Franklin to play after he was rested against the Tigers but are wary of the Swans' multi-pronged attack.
Rutten said Essendon would resist the temptation to swing Cale Hooker into defence after the versatile tall booted five goals against St Kilda, while Peter Wright will continue to play in the ruck.