West Ham United fullback Lars Jacobsen admits Wayne Rooney was world class in Manchester United's victory on Saturday.
Rooney struck a hat-trick in the 4-2 triumph.
Jacobsen told whufc.com: "Perhaps you could say that [we defended too deep in the second half], because when you concede goals there are always reasons for it. They scored a free-kick goal and in the first half we had a similar chance that Thomas just missed slightly and I think that was the difference.
"I think Rooney's second goal was a superb touch and a superb finish and sometimes you have to acknowledge that they have world-class players and I think that's why they scored four goals. The last goal, I don't think we would have conceded that if the game didn't develop in the way it did.
"It's not nice to concede four goals in 45 minutes so as a defender, I and my colleagues have to ask ourselves what we could have done better."
