STAR Geelong defender Tom Stewart looks set for a long stint on the sidelines with a broken collarbone.

The two-time All-Australian engaged in some bumping with Melbourne forward Tom McDonald off the ball in the first quarter and headed to the bench immediately.

Stewart may require surgery, but the Cats haven't put a timeline on his return just yet.

"The feedback I've got is that he's broken his collarbone," Geelong coach Chris Scott said.

The Cats coach didn't have too much to say on the incident and thought it was relatively innocuous. 

"He could have done that in the warm-up, couldn't he?" Scott said.

Stewart's injury could pave the way for a return for defender Lachie Henderson, who Scott insists is right in the frame for selection thanks to outstanding training form.

The Cats have another concern with forward Tom Atkins who could "barely function" towards the end of the game.

"Tommy Atkins was sore, he was hobbling around with a couple of different things, and that's a concern for us because he's as tough as they come," Scott said.

"We're optimistic that it's not going to be something that keeps him out, but that's a tough one because it was really important for us that he helped us with our rotations, but it was hard to watch him labouring as he did."

Star midfielder Patrick Dangerfield got a knock to his jaw, but he's adamant he'll be right for next week.