Collingwood defender Lynden Dunn will have scans in coming days as the club fears he suffered another serious knee injury in his comeback game at VFL level.  

The 31-year-old backman missed the second half of last season after rupturing the anterior cruciate ligament in his knee.

In Thursday night's practice match against Richmond at Punt Road Oval, played ahead of the Richmond and Collingwood clash at the MCG, Dunn twisted awkwardly and then hobbled from the field in the hands of a trainer.

He played no further part in the game as Collingwood's medical personnel tested the same leg as last year's injury to determine the extent of the damage.

Collingwood coach Nathan Buckley, speaking after the Magpies' win over Richmond, said he did not relay the news to his team ahead of its game, but added the early diagnosis didn't look promising.

"We didn't mention it pre-game, but we believe that it filtered through to the boys in varying stages in the half an hour before we took the field," he said.

"The prognosis is not good, but we'll obviously wait for scans on that, but 'Dunny' is a much-loved member of our football club because he's a member of our football club. He gives so much of himself and he has contributed so much since coming across from Melbourne.

"We really value what he brings to the table on and off the field, and his teammates will rally around him regardless of what the final scan shows."

Dunn is into his third season at Collingwood after 11 years and 165 games at the Melbourne.