The Geelong Cats may be without Gary Rohan for the first month of the season, with the forward dealing with another injury concern.

7News journalist Mitch Cleary reports that Rohan has been dealing with a hamstring injury and has yet to return to full training.

The reporter revealed that he could miss the first month of the season. This new injury concern comes after he had several issues with his back during the pre-season.

A club veteran, the premiership winner was already in doubt for the club's opening match this week and was a notable absentee for the Cats during the pre-season matches.

Geelong only has one other player on their injury list to begin the season, midfielder Cameron Guthrie. Guthrie is set to spend at least the first two months on the sidelines after sustaining a quad injury.