The injury cloud hovers uncomfortably over Collingwood big men Nathan Brown and Quinten Lynch on the eve of their sudden-death AFL final.

Both Brown, who has a knee problem, and Lynch (ankle) are still no certainties to play in the Magpies’ clash with Port Adelaide at the MCG on Saturday night despite being named in Collingwood’s 22, admits assistant coach Matthew Lappin.

The duo must train well on Friday and pull up the same way, or risk missing out.

“(Lynch) has got to get through the session today,” Lappin said.

“He had a run yesterday and he’s improved a lot as the week’s gone on.

“(Brown) is the same. He’s got the session to go, and we’re very hopeful they’ll get through.

“If Quinten Lynch or Nathan Brown doesn’t come up in the session we’re going to have to replace players, so it’s a squad of 25 at the moment and we’ll see how we go.”

Lynch failed to train on Wednesday.

But the Magpies will certainly have midfielder Luke Ball and wingman Harry O’Brien back from injury and illness.

Lappin said Collingwood have spent the week virtually freshening up players following Sunday’s narrow loss to North Melbourne in a dead rubber match.

But he has no concerns about his side handling the short break.

“It was a funny game, but our players have freshened up really well this week,” Lappin said.

“Some of our best games this year have come off six-day turnarounds, so we’re certainly not worried about that.”

Port Adelaide beat Collingwood by 35 points in round 14.

But Collingwood have since shown with wins over Essendon, premiers Sydney and West Coast they are finding fluidity at the right time of the season.

Port regain star midfielder Hamish Hartlett from suspension and Robbie Gray and defender Alipate Carlile.