KNEE surgery for Fremantle defender Connor Blakely will keep him out for up to six weeks. 

Blakely suffered the injury to the cartilage in his right knee at training on Wednesday and was helped from the ground.

His operation will reveal how badly hurt the 22-year-old is.

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"The medical advice at this stage is that Connor has damaged the meniscus in his right knee and we are awaiting the results of an arthroscope," football manager Chris Bond told

"At this point, Connor is likely to miss up to six weeks."

Blakely ranks eighth in the competition for total marks taken and is averaging 24 disposals per game.

The Dockers are 6-7 and face Brisbane at Optus Stadium on Sunday.