Juan Mata insists there is a belief in the Manchester United dressing that they can win the Premier League title this season but the midfielder accepts Jose Mourinho's team may need "some luck" to lift the Champions League.
United have started the season with three wins to sit top of the table with a perfect record.
It will be put to the test against Stoke at the bet365 Stadium on Saturday. But Mata says there is a growing confidence at Old Trafford after their flying start.
He said: "The belief is always there. When you play for such a club you start every competition believing that you can win it.