Sydney spearhead Lance Franklin is likely to miss four to six weeks after injuring his right hamstring at training on Wednesday.
The Swans confirmed Franklin injured his hamstring during a routine running drill. He immediately pulled up, walked off the training track and did not return.
The club is now assessing the severity of the injury, but Sydney's General Manager of Football Charlie Gardiner said it wasn't looking good for the immediate future.
"The medical team received the results today and confirmed it's a decent hamstring injury," Gardiner said in a statement released late Thursday.
"It's on his right side and he has no history of injury to that side. He won't run for the next three-to-four weeks but the positive is there's no tendon damage in the hamstring.
"We think it's slightly worse than the injury he sustained last year mid-season, and he missed about nine weeks, so that might be an indication but we just don't know until he gets into his rehabilitation and we see how he progresses."
The injury comes a fortnight after Sydney confirmed the four-time Coleman Medal winner had fully recovered from a knee arthroscopy he underwent in January. He was expected to suit up for the Swans' return clash against Essendon at the SCG on Sunday, June 14, but that is now unlikely.
Compounding Sydney's misery is the injury to fellow forward Sam Reid, who suffered a calf strain at training on Monday. The Swans say he is also set to miss their Round 2 game against the Bombers.
Franklin, 33, missed 12 games last season through a series of injuries and did not play in Round 1 this year. Stuck on 944 goals, he is currently looking to become the sixth player in VFL/AFL history to kick 1,000 career majors.