Nick Riewoldt and Jack Ziebell are each facing a stiff battle to overcome injury in time to play next weekend, while Ollie Wines, Adam Cooney and Chris Knights are facing longer stints on the sidelines.

As of late Sunday, Ziebell was still in hospital, where he was taken after coughing up blood following a collision in North Melbourne's loss to Port Adelaide on Saturday night. He was diagnosed with bruised lungs from the incident in which he clattered into the back of Wines in an attempt to spoil the Power midfielder from marking the ball. The Kangaroos said he would be monitored during the week to gauge his availability for Sunday's match away to Geelong.

Riewoldt was a late withdrawal from St Kilda due to what the club said was a low-grade calf strain. Saints coach Alan Richardson said the captain was "no certainty" to recover in time to play in Saturday's Anzac Day match against Carlton in New Zealand, while veteran Leigh Montagna said Riewoldt would be "touch and go" to face the Blues.

"He does have a slight nick in his calf. We do know that when you get older, calfs can be tough to get over, so whether you sacrifice one week or a couple of weeks to save yourself four [weeks, in case of aggravating the injury has to be decided]. But knowing Nick, he'll be pretty keen to play, so we'll just have to go by [how he recovers] as the week goes on," Montagna told AFL Game Day.

Montagna said he would play his first match of the season on Saturday, although Richardson seemed to rate him only rated as "a chance" to sufficiently recover from bone bruising in a knee.

One player sure to be missing on Anzac Day, from the traditional Essendon-Collingwood match at the MCG, is Adam Cooney. The Bombers' recruit suffered what coach James Hird described as a "garden-variety" hamstring strain that would likely sideline him for at least three weeks.

Essendon defender Cale Hooker lamented Cooney, 29, would miss his first opportunity to play in a marque match since his arrival from the Western Bulldogs at the end of last season.

"He'd be really disappointed," Hooker told AFL Game Day. "He was in good spirits after the game, but I'm sure inside he's really hurting. He's come to the club and really added a bit of class and a bit of speed on the outside. The boys love him and we're really going to miss him for the next three or four weeks."

Port Adelaide are bracing for rugged midfielder Wines to be missing for at least a month with a dislocated wrist, in what will be his first stint out of the senior team since he was drafted at the end of 2012.

"He'll possibly miss somewhere between four and six weeks, I'd reckon," Power coach Ken Hinkley told SEN.

Wines' captain, Travis Boak, said they were hopeful of regaining ruckman Matthew Lobbe for the first time this season for their match against reigning premiers Hawthorn on Saturday night.

The wretched injury run of Richmond small-forward Chris Knights continued. The 28-year-old's first senior appearance in almost two years, owing to a serious knee injury he suffered early in his first season at the club, ended prematurely, due to a hamstring strain that will see him unavailable for the Tigers' match against Melbourne on Friday night.

Knights will undergo scans on Monday to determine the extent of damage to his hamstring. His coach, Damien Hardwick, expressed his disappointment for Knights after the team's win on Brisbane on Saturday night.

"He's made his way back in the side, he's had a tough journey. We feel for him," he said. "It's a sad state of affairs ... he's just had a wretched run with injury and no luck at all."