Manchester United boss Louis van Gaal explained hooking Paddy McNair before halftime during victory at Southampton.

He was substituted after only 39 minutes at St Mary's Stadium on Monday night during Manchester United's 2-1 victory over the Saints.

Van Gaal said: "He (McNair) hadn't any confidence. He had already given three big chances away.

"I had to (substitute him), it's very disappointing for me and also for Paddy, but I had to because as a manager, I'm responsible to win.

"And I think, after the change, we played a little better.

"Of course, it's tough (for McNair), but it's also in his best interests."