ESSENDON ruckman Tom Bellchambers has suffered a setback in his preparations for a blockbuster round one return to football, with a knee injury set to sideline the big man for two months.

Meanwhile, Joe Daniher is also battling a knee complaint, although the Bombers spearhead should be fit to appear during the pre-season JLT Community Series.

Bellchambers, one of 10 Bombers aiming to return from doping bans in a Saturday night round one clash against arch-rivals Hawthorn on March 25, had been on modified duties recently but now requires surgery. 

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

"He 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." 

Daniher, who led Essendon's goalkicking with 43 majors last season, is unlikely to be available for the opening pre-season clash against Collingwood on February 16. 

But the 201cm star is set to return to full training in the next two weeks and could be fit to face Gold Coast 10 days later or Geelong in Bendigo on March 12.

"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."

In positive news, recruit Josh Green has joined full training after overcoming a foot problem which hampered the zippy small forward's final season in Brisbane. 

"Josh started with us with the background of two different foot stress issues," Crow said.

"He’s been brilliant – we’ve been really impressed with the way he’s been able to transform his body. 

"He’s done matchplay over the last couple of weeks, he’s doing full work at training this week."

Shaun McKernan is also back into match practice after undergoing wrist and ankle surgery at the end of last season, while 203cm ruckman Sam Draper has resumed running after arriving at the club with knee tendinitis.

Draper was the first pick in last year's NAB AFL Rookie Draft.