ESSENDON skipper Jobe Watson expects to miss four weeks after breaking his collarbone in Sunday's win over Port Adelaide.

Watson suffered the injury during the first quarter and was subbed out.

The reigning Brownlow medallist told Fox Footy after the game club doctors expected him to be out for four weeks. 

"It looks like a pretty simple break," Watson said. 

"It doesn't matter. That's footy. 

"The pain wasn't too bad," he added.

Watson left the ground after the Power's Justin Westhoff bumped him in a contest in the middle for a ground ball and went straight down into the rooms. The bump was fair as both players collided shoulder to shoulder.

Watson reappeared on the bench soon after to accept the red substitute vest and immediately had ice applied to his left shoulder.

Coach James Hird said Watson was likely to undergo surgery on Monday morning.

"He's a huge loss for us, he was playing pretty well for us before he got hurt," Hird said.

"He's our captain and spiritual leader and all those things that he brings to our game ... it's a big loss. 

"The one positive out of tonight through that injury was a lot of other players stood up and took the slack from a leadership point of view. It's disappointing but it gives other players an opportunity."

Fellow midfield star Brent Stanton will also be assessed also suffering a leg injury in Sunday evening's first half.

Stanton was kicked on his ankle/heel area, and played out the second half of the game hampered.

Hird praised the 27-year-old for playing through the injury to make sure the Bombers were not short of interchange rotations. He finished with 23 disposals. 

"We're not exactly sure what it is, but he was able to play at 80-85 per cent, and I thought his game tonight after half-time, when he came back on with that injury, was terrific," Hird said. 

"[He kicked] two goals, got a fair bit of the ball, defended really well, and enabled our rotations to happen. 

"I thought we really tired towards the end of the game and without 'Stants' performing that role it might have been a different story tonight.

"It was a huge part of us winning tonight – Brent Stanton being able to stay out on the ground."