The 24-year-old has played the past three games in the VFL, and had been an emergency for the seniors in the past fortnight.

But he has been unable to get his fitness to the level required for the AFL due to this soreness, which Essendon coach Mark Thompson yesterday said was unrelated to his ankle.

"It's a bit of a concern for us," Thompson said yesterday.

"I think they're trying things to get him right so he can play a game at the AFL level, which he's not capable at the moment.

"He's definitely in our best 22. He was hunted and hounded by all the other clubs to get him to their club.

"He's a very good player for us and we need him back."

Thompson said he had recovered well from his first VFL outing, but things had gone downhill from there and there was no way to forecast how he would recover in the future.

Bellchambers strained ligaments on both sides of his left ankle after landing on teammate Michael Hibberd's foot at training in January, with surgery repairing the lateral and medial ligaments and cleaning a small amount of cartilage damage.

The 202-centimetre, 108-kilogram big-man is a vital part of the Essendon make-up, with his unavailability heavily impacting the ruck and in attack.

He was among Essendon's best players last year, averaging 22 hitouts, kicking 28 goals (the second most at the club) and averaged 10 disposals a game in his 18 outings.

The eighth pick in the 2008 preseason draft, who was heavily linked to Greater Western Sydney last season before re- signing with the Bombers, has played 61 games in the red and black.