Adelaide United have said they are realistic in regards to Lloyd Owusu's swine flu case.

The former Cheltenham Town striker has been hit by the influenza and has been kept in isolation for the past two weeks but it seems he may have to miss the start of the A-League season.

"Realistically I would say anywhere between six-to-eight weeks," Vidmar said on Tuesday.

"Certainly we don't want to push him too early and try and force and rush him back into the team where he might end up getting extra niggles, so we're going to be really cautious with him and if it takes us six, seven, eight weeks then that's how it is.

"He's got probably 15-20 years of being a professional footballer so he's got that condition in his body so it won't take long for him to get up to speed.

"In saying that, he needs a decent base to make sure he lasts the rest of the season so that's the first thing we'll be working on."