AFL club Hawthorn will be without gun midfielder Sam Mitchell for eight weeks.
Scans on Monday confirmed Mitchell had suffered a serious hamstring injury in Saturday's 145-point win over St Kilda.
Key defender Brian Lake tweaked his calf in the match and will be out of action for three to four weeks.
Mitchell does not require surgery, but the nature of the intra-muscular hamstring tendon injury means he's unlikely to return until round 16 when the Hawks tackle North Melbourne on July 4.
The reigning premiers will sorely miss the two veterans on Friday night when they face Sydney at ANZ Stadium.
The Swans are also dealing with their own injury concerns, most notably ex-Hawthorn superstar Lance Franklin's knee.