Melbourne Heart's Alex Terra is finding it hard to keep himself fit according to coach John van 't Schip.

The speedy Brazilian has been impressive in eight matches for the new A-League club so far this season but van 't Schip said he was a week-by-week proposition at the moment.

"It's difficult to say," the Dutchman said of Terr's availability for next Wednesday's North Queensland Fury clash.

"Alex every time we think he can play then he gets a little injury and drops behind for a few days.

"Now he's on a good program so hopefully he can be available for the game, if not he will be available for the game after against Brisbane."