Sydney midfielder Harry Cunningham will miss the next six weeks after suffering an injury in the Swans' win over St Kilda on Saturday.

The 23-year-old sustained a partial tear in his ankle at Etihad Stadium on the weekend, and will now miss the middle part of the season with the injury.

John Longmire's men have now won their past three matches, following an 0-6 start to the season, and are now just two games outside the eight.