Louis van Gaal has claimed that there is more to come from Sergio Romero following a promising start to his Manchester United career.

The speculation surrounding the future of David de Gea, who could reportedly still move to Real Madrid before the transfer deadline, persuaded United to bring in another goalkeeper in the summer and Romero arrived at Old Trafford on a free transfer.

Romero has kept four clean sheets in five competitive matches, but Van Gaal is confident that the Argentine will improve when he is tested more regularly.

"I don't think he is up to it yet because, until now, we haven't allowed a lot of shots or moments in our 16-metre area," the Dutchman told reporters.

"I think he has made very good saves but until now I think only maybe the save in Brugge at 1-0 was very important, but he did also a save against Tottenham.

"So he could not show what he can show, I think, but that is only a compliment for the team. We wouldn't have bought him if we didn't believe in him."

United will look to extend their unbeaten run when they visit Swansea City on Sunday.