PORT Adelaide recruit Charlie Dixon's pre-season has been derailed for at least a month after knee surgery.

The club said the former Sun had suffered minor damage to his left meniscus at training on Monday and had surgery on Tuesday. 

Dixon, 25, went to ground with a knee scare at training in mid-January, but completed the session.

At the time the club dismissed any concerns.

It's not clear if this week's incident is in any way related. 

Port's head of high performance, Darren Burgess, was optimistic that Dixon could still feature late in this year's NAB Challenge. 

"His operation was pretty straightforward and we’ll be able to get him through his rehab by the end of the NAB Challenge," Burgess said.

"Charlie's done every session - hasn't missed one - we've been really happy with what he's been doing and he's in fantastic shape," he said.

"He'll probably need only two weeks off his legs, in that time he'll be on the bike, swimming and whatever else we can do to keep his fitness up.

"We're aiming for round three of the NAB [Challenge] but our main priority is round one ... all of our attention will be focused towards that."