The Brazilian will be rested as a precaution rather than being forced to miss with a serious injury which was confirmed by United assistant Mike Mulvey.
''Robbo had an injury interrupted pre-season. He was a yard or two off his personal best against Brisbane Roar last weekend," he said.
''He is not 100 per cent yet. He's a valuable player but it's a long season. Luckily we have a lot of depth, so we can give him time.''
Former Manchester United defender John Curtis will also be left out of the squad because of a calf injury.