SYDNEY, AUSTRALIA - APRIL 04: Joe Daniher and Tom Bellchambers of the Bombers look dejected after losing the Round One AFL match between the Sydney Swans and the Essendon Bombers at ANZ Stadium on April 4, 2015 in Sydney, Australia. (Photo by Cameron Spencer/Getty Images)

Essendon has suffered a big injury blow, with ruckman Tom Bellchambers set to be sidelined for up to two months with a knee injury, putting him in danger of missing Round 1 against Hawthorn.

Bellchambers had been on a modified training program due to a knee complaint, but will now require surgery.

Fellow big man, Joe Daniher, also has a knee issue and will be on a reduced training load.

“Tom, like Joe, has a knee surface issue from a number of years ago that raised its head before Christmas,” Essendon high performance manager Justin Crow said.

“He (Bellchambers) was in rehab after a rest and progressing well until a week ago.

“He’s not quite at 100 per cent so today we sought the advice of his specialist, Julian Feller, and Tom is going to go in for a clean-out of his knee to try to get him to 100 per cent.

“Tom will start running in a month, he’ll build up his football over a month after that and then he’ll be pushing for selection.”

However, Daniher should be able to return to full training in around a fortnight.

“We’ve got to find the balance between filling Joe’s tank up for the season and also getting him to the point, from a football point of view, where he’s ready to play at a high level,” Crow said.

“We’ll be weighing that up as we go but I’d be thinking more the later end of the Community Series, than the front end.”