Hille was cited for rough conduct after a hit on Brendon Goddard in the opening quarter of the Dons' upset 12-point win.
The veteran was among his side's best, kicking four goals as he rotated between the ruck and the forward line with improving teammate Paddy Ryder. But the report could see him sidelined when the Bombers aim to improve their season record to 4-5 in next week's clash against Richmond.
Hille beat a ban in round one after his matchday report for charging Geelong's Jimmy Bartel was thrown out by the match review panel.
"He's such an important player for us - we can't afford him running the gauntlet week-in, week-out," Knights said after Sunday's match.
"There have been two or three instances this year, but the pleasing aspect is that he was trying to demonstrate that he wanted to will himself on the contest.
"Getting his technique right is important. I feel he can still will himself on the contest without getting reported."
There was further bad news in the bruising victory, which Knights said was proof the Bombers had developed "some consistency in our football".
Key defender Cale Hooker injured his hamstring, and Knights said early prognostications suggested a 3-4 week absence.
Knights also confirmed big man Jason Laycock broke his foot in Saturday's VFL game.
"That's a little bit of a blow," Knights said. "He was playing pretty well before he did his injury"
