St Kilda's Sam Gilbert has had surgery for a stress fracture in his foot, forcing him to miss the early part of the season.
Gilbert will not run for six weeks, meaning that with round one for the Saints only seven weeks away, he will not be available for the first match against Melbourne on March 22.
Saints football manager Chris Pelchen was uncertain how many matches the 27-year-old would miss.
''Sam reported soreness last week in his foot and it just got sorer and sorer to the point where we had it scanned and found a small stress fracture,'' Pelchen said.
''Fortunately it is not the navicular but it is a small bone in his foot that he had operated on with a screw inserted. We would expect he he would miss the first game but after that it is a mater of wait and see how his foot reacts when he starts running again.''
Gilbert missed a large part of last season after suffering a knee injury against Collingwood in round six.
Collingwood has also opted for surgery for its first draft pick, Matthew Scharenberg.
The 18-year-old South Australian, recruited with pick six in last year's draft, had a small bone in a toe on each foot removed.
He is also not expected to be able to run for four to six weeks, but Collingwood football manager Rodney Eade said the operation should give certainty around his recovery program and he should be available to play mid-year.
"It doesn't drastically change the scenario for Matthew, who only turned 18 a few weeks before the draft," Eade, said. "He is a very talented player but he is young and we were always taking a long-term approach with him.''
Port Adelaide also suffered a blow with ruckman Jarrad Redden sidelined for up to 10 weeks after knee surgery.
''This is a decision based on getting Jarrad right so he can play as much football as possible in 2014,'' Port coach Ken Hinkley said.