Prismall was recruited to the club at the end of 2008 having already ruptured his anterior cruciate ligament in that season's finals series playing for Geelong.
On Sunday against Collingwood, he was stretchered off the ground in the first quarter having torn the ligament in his left knee, but Essendon coach James Hird said Prismall would be at the club next year, despite his three-year deal ending this season.
""We'll offer Brent a new contract,"" Hird said from Etihad Stadium on Friday.
""Obviously we'll have to look at the terms and everything of that contract, but Brent's a required player and we're pretty sure he'll be here next year.""
Prismall has played 36 games for the Bombers in three seasons for a total of 61 since making his debut in 2006 for the Cats, but Hird said he should be available for the second half of next season.
""It's a different knee and I think he's had a history in his family of knee reconstructions so it's an injury nobody ever wants to see happen,"" Hird said.
""There's a lot of football left in Brent Prismall and he should be back by May next year, so it's not the worst thing that can happen in his career.""
Prismall and Travis Colyer will miss Saturday night's clash with the Sydney Swans at Etihad Stadium with their season-ending injuries, but the Bombers have welcomed back injured trio Heath Hocking, Dustin Fletcher and Michael Hurley.
""We were unsure if we'd get Heath back this year, but his foot has come up really well after two weeks rest and Fletcher's come off the corky, and Michael Hurley is looking pretty good,"" Hird said.
""They're three good players to have in there, but they all have to play well for us to be a chance on the weekend.""
Dual Brownlow Medallist Adam Goodes starred in the Swans' five-point defeat of the Bombers in round two this season, and Hird said Patrick Ryder, fresh from his excellent defensive effort on Travis Cloke last week, would be strongly considered for the job on Goodes.
""He's a very good chance,"" Hird said.
""I remember Kevin Sheedy saying that he'd love to play Paddy Ryder on [Hawthorn's] Lance Franklin consistently and we all scoffed a bit that it wouldn't be a possibility.
""But he knows how to defend. Adam Goodes is an out-and-out star that coaches have nightmares about where he’s going to play. Paddy comes into contention there,"" Hird said.