COLLINGWOOD will be without midfield recruit Levi Greenwood until midway through the season after scans revealed he had suffered a hairline fracture in his right ankle.

The Magpies estimate the 26-year-old will be off his ankle for about six weeks before entering a rehabilitation program.

The injury occurred when his foot was trapped under Western Bulldogs forward Jarrad Grant during a tackle in the third quarter of Saturday night's game at Etihad Stadium.

It is a massive blow for Greenwood who joined Collingwood on a four-year deal at the end of 2014 after completing a breakout year with North Melbourne.

"He will be off it for about six weeks and after that it will be however long it takes him to run again," director of football Neil Balme told the club's website.

The Magpies also said defender Ben Reid was unlikely to play in round one with the club taking a conservative approach to his recovery from a hamstring injury.

He said Paul Seedsman and Darcy Moore played in Collingwood's VFL trial match on Friday and would play again against the Tigers on Thursday night in a VFL practice match.