IN-FORM Collingwood ruckman Brodie Grundy is in doubt for Sunday's clash against Brisbane at the Gabba as he battles shin soreness.

Grundy has averaged 23 disposals this season and is ranked No.9 in the competition for contested possessions per game.

The 24-year-old started extremely well in Sunday's loss to Richmond at the MCG but saw his output diminish as his Tigers counterpart Toby Nankervis put in a stellar performance.

"I've had a bit of a shin problem over the last few weeks and it flared up on the weekend, halfway through the second," Grundy told Channel Seven on Monday.

The big man wasn't overly optimistic when asked if he would be fit to face the Lions.

"I'm not sure at the moment. I hope so," Grundy said.

The Magpies are battling a lengthy injury list with James Aish (left knee) and Ben Reid (Achilles) set for extended stints on the sidelines after being hurt against the Tigers.