Fremantle's All-Australian defender Michael Johnson could be out for a month after injuring his knee against Adelaide at Patersons Stadium today.
Johnson was substituted out with a right knee injury at half-time in the 40-point win over the Crows.
The 2013 All-Australian injured the leg in a slinging tackle late in the second term and spent the rest of the day on the bench nursing some crutches.
"He's got a slight medial (strain), maybe a grade one, maybe a grade two," coach Ross Lyon said. "That's anywhere from two to four weeks. So he won't play in the near term."