Sydney forward Lance Franklin has undergone scans after leading the ground injured in last night's win over Hawthorn at the SCG.

The scans have confirmed that Franklin has suffered a strain in his hamstring.

Head of Football Charlie Gardiner said the prognosis would be worked through with the medical staff early in the week.

"Lance had a scan this morning which confirms a strain to his hamstring," Gardiner said.

"It appears to be a similar injury to the one he sustained leading into round 6.

"We will know more once he is assessed by the medical team early next week but early indications are that he will miss 3 to 4 weeks.”