ST KILDA'S brilliant opening to the season has brought a significant setback, with key defender Matt Maguire expected to miss the next six weeks with stress fractures in his battle-scarred left leg.

Geelong, too, has had a loss of similar scale after new skipper Tom Harley had finger surgery yesterday. The Cats said Harley would be missing for the next six matches.

Harley tore a tendon in his left hand on Sunday against the Bulldogs and while he might have played on with the injury, the Cats opted to take no risk and deal with the injury immediately.

"There was a chance that Tom could have battled through the season with the injury, but the specialist felt he would need to have it operated on before the end of the season, so the best decision was to have it done now," Geelong football manager Neil Balme said on the club website.

St Kilda will be conservative with Maguire, given that he was recovering from a severe broken leg when stress fractures reared in the same leg.

While a foot and ankle specialist will determine the extent of Maguire's injury today, St Kilda club doctor Ian Stone said it was believed to be a regulation stress fracture.

Such an injury would normally require four to six weeks, but Maguire's recent history — he had multiple operations to the left leg he broke late last season to prevent him from developing Compartment syndrome — means the Saints are likely to give him the full six weeks.

Maguire's situation is often compared to that of Richmond's gun forward Nathan Brown, who is now sidelined with a stress reaction, or "hot spot" in the same leg he broke back in 2005 in an injury even more gruesome than Maguire's.

Stress fractures, or reactions, like those to Maguire and Brown — the latter was forced to miss several weeks with soreness last year — are a risk for players recovering from injuries that require a prolonged immobilisation.

Maguire had made a rapid and encouraging recovery from the broken leg, which ended his season in round 18 last year. Understandably, he was said to have been flattened by yesterday's setback.

Collingwood's young defender John Anthony will not play again in 2007 as a result of a neck injury sustained in the pre-season. The Magpies have confirmed that Anthony, who hurt his neck in a collision at training back in February, has been advised by specialists not to risk further injury and to have a nine-month lay-off from football.

But Magpies football chief Geoff Walsh said that Anthony, who was expected to play senior football and is regarded as an excellent key defensive prospect, also had been told that he would recover from the injury and would be fine to play in 2008.

While Anthony's unavailability for 2007 is a blow to the Magpies — who already have lost forward Sean Rusling for much of the first half of the season with a shoulder injury — they are on the verge of regaining All-Australian forward Alan Didak.

Walsh said provided Didak trained well, he was likely to make his return with Williamstown in the VFL this weekend. Didak has made a swift recovery from a knee reconstruction he had in September.

Anthony's injury involves bleeding in a blood vessel in the neck around the spinal cord, hence the neurosurgeon's recommendation that he not play competitive football for nine months. Anthony's initial diagnosis had been more optimistic.

Anthony, a second-year player, is the second Magpie to be afflicted with a delicate neck injury in a matter of months, with veteran forward Blake Caracella forced to retire in the middle of the 2006 season.

Caracella was fortunate to escape paralysis in a collision with Brisbane Lion Tim Notting.

The club can elevate a rookie in his place if it wishes.