ADELAIDE coach Neil Craig says utility Scott Stevens is still suffering from post-concussion syndrome and is unlikely to be available for AFL selection until later this season.

Stevens hasn't played since suffering a head knock at training six weeks ago.

It was the fourth documented concussion the 29-year-old had suffered in the past two years.

He missed three games after being concussed against Fremantle in round one last season and sat out Adelaide's clash with Geelong in round four, 2009 for the same reason.

He also missed the club's NAB Challenge game against Freo at Thebarton Oval in March this year after copping another knock at training.

Stevens, who has been troubled by headaches and nausea, has seen a specialist and passed the medical tests necessary to start training and playing, but Craig said the former Sydney Swans forward still wasn't feeling "quite right".

"Scott's most important thing at the moment is his health. He's fine. He's been here at the club all day helping us coach, but he's not ready to start exercising," Craig said.

"We don't want him to keep trying to [exercise] and then go backwards. From a medical point of view he's ready to go, but in the end, the most important test is how Scott feels.

"He'll come good and hopefully he'll be back in our team towards the end of the year."

Craig denied Stevens was pondering retirement as a result of his latest setback.

The reliable veteran remains on the Crows' injury list, but two other players, Andy Otten (knee) and Daniel Talia (Achilles), have been cleared to play for South Adelaide on Saturday.

Wingman David Mackay has started non-competitive training drills and is expected to make a return in the SANFL next month.