KANGAROOS key forward Nathan Thompson is trying to stay positive despite his season-ending knee injury.

Thompson, the Roos' leading goalkicker in the past two seasons, left hospital yesterday after weekend surgery on the knee he injured in a practice match against St Kilda.

"I've got two beautiful kids, with another one on the way, so I'll be giving them plenty of time this year. I've got plenty of things to keep myself busy," Thompson said.

"You can't get too down in the dumps over something like this."

Western Bulldogs veteran Chris Grant has been cleared of a tear to his groin and could be available for the first-round game against Geelong at Telstra Dome.

He injured his knee during Saturday's practice match win over West Coast.

The news for Geelong ruckman Steven King was not so good and he is expected to miss the opening-round clash with the Western Bulldogs because of a calf strain.

King received a kick to the calf in Saturday's practice match against Melbourne and the club rates him unlikely to play against the Bulldogs.

It continues a poor run for the former skipper as he battled leg muscle injuries last year.

AAP