COLLINGWOOD defender Marley Williams will be sidelined for up to a month after scans confirmed he suffered a midfoot sprain in Saturday's loss to St Kilda.

The 22-year-old injured his foot after colliding into Saints backman Sam Gilbert in the first half of the Magpies' 29-point defeat at the MCG.

Buckley confirmed Williams would miss the next "three or four weeks" and be required to wear a protective moon boot for the next fortnight.

"He's had a sprain in his foot, so he's injured a ligament there that'll be in a boot for two weeks," Buckley told Fox Footy on Monday night.

"Then we'll see how it goes on the other side of it.

"We've played 12 defenders in the first three weeks so we're looking for a little bit of continuity."

Defender Alan Toovey staked his claim for a senior call-up in Williams' absence after collecting 24 possessions, 11 of which were contested, in the VFL on Sunday.

The Pies will also regain midfielder Steele Sidebottom from suspension after serving his two-match ban for his head-high bump on Sydney Swan Dan Hannebery in round one.

Meanwhile, ruckman Jarrod Witts has had a setback after he split the webbing in his hand in the second half of Collingwood's season opener against the Swans.

Magpies football manager Neil Balme said Witts would miss another week to nurse an infection that had developed.

"He was coming good when he split the webbing in his hand, but he had an infection in it and it needed to be fixed," Balme told the club's website on Monday.

"He'll probably miss this week as well, but he should be right the week after."