INJURY prone Geelong big man Mitch Clark is back running again as he begins his recovery from the calf injury that has plagued his pre-season.

Clark, who hasn't played senior football since round nine last season, has had a history of soft-tissue injuries and has been battling a calf problem since January.

Geelong physiotherapist Mark Young told the club's website the talented Clark is back on the training track, but taking it very slowly.

"All indications are good at this point, but it's someone we're not going to rush," Young said.

Meanwhile, defender Jackson Thurlow will have surgery on Thursday to repair his ruptured ACL after injuring his right knee in week three of the NAB Challenge against Essendon.

The promising Cat, who turns 22 on Easter Monday, will miss the rest of the season and was placed on the long-term injury list this week.

Young also revealed that rookie Tom Read recently underwent surgery to remove a small cyst.

"He had mysterious knee pain that we have gone to surgery with. He had a small cyst that we have removed. There was no structural damage," Young said.

"We're confident he'll go well."

Recruit Scott Selwood remains several weeks away from full fitness as he recovers from ankle surgery, but mature-aged rookie Sam Menegola began running this week after straining his PCL in the first NAB Challenge game.

Injury prone defender Cameron Delaney had surgery to both knees in early January after battling a foot complaint last season.

"He's running well now and he'll start to join in training in the coming weeks," Young said.

Unlucky utility Billie Smedts is expected to return to full training in the next couple of weeks after an operation to repair a dislocated shoulder.

The Cats expect captain Joel Selwood to be fit for the season opener against Hawthorn on Easter Monday.