Kurt Tippett in race to face Brisbane Lions

KURT Tippett has three days to reach his "baseline" concussion mark to play against the Brisbane Lions at the Gabba on Saturday night.

KURT Tippett has three days to reach his "baseline" concussion mark to play against the Brisbane Lions at the Gabba on Saturday night.

After missing Adelaide's past three matches with the after-effects of three heavy head knocks suffered in five weeks, Tippett is said to be "desperate" to play against the club which has been courting him.

But the ace key forward still needs one final tick of approval from the club's doctor, Andrew Potter, before being passed fit to play.

Potter on Friday ruled Tippett out of the Crows clash against Fremantle after he had been named in the side.

Tippett trained strongly at Max Basheer Reserve yesterday, with young team-mate Lewis Johnston declaring he looked "perfect".

But football operations manager Phil Harper said Tippett still needed to be cleared by the doctors.

"He's been through a series of tests ... but in the end they didn't last week feel like he was back to his baseline (mark) of brain function," Harper said.

"He's trained flat-out for two weeks, he wants to play desperately but the doctors have to be convinced he's 100 per cent back to his baseline."

The concussion test Tippett must pass is one of "speed and accuracy" where he will have to reach the concussion test standards he set in the pre-season.

Small forward Jason Porplyzia is expected to play against the Lions after missing the Dockers clash with shoulder bruising.

Johnston, meanwhile, is on standby should Tippett fail to convince the doctors he is ready to return.

The former Swan played his first game for Adelaide on Saturday after being recruited from Sydney, where he played two matches in three years, at the end of last season.

Playing as a key forward, the No. 12 pick at the 2008 national draft managed a modest seven disposals and five marks but coach Brenton Sanderson liked what he saw.

"He was okay, he tried his heart out," Sanderson said. "Sometimes it's difficult coming into a side late in a season when you've played in the competition down (in the SANFL) for the majority of it.

"He got himself into the right spot a couple of times but the boys didn't see him.

"A few times you could tell that the game was just a little bit quick for what he is used to but he is a beautiful kick and a few times he had the ball in his hand he used it really well.

"He's going to be a really good player for us," Sanderson said.

Johnston, 21 and powerfully built at 193cm and 91kg, admitted he struggled with the pace of the game in the first half.

"It was definitely a much quicker and different game style compared to what I've been playing lately (with North Adelaide)," he said.

"But in the third quarter I started to adapt to it and got into it better, which was good.

"Obviously I am wanting to play (AFL) again this week but if not, I'll just go back to North and try to play as well as I can and try to force my way back into the side," Johnston said.