Chelsea striker Didier Drogba scored the only goal of a disappointing first cup final at the new Wembley in extra time.

United appeared to have forced the ball over the line in a goalmouth scramble early in extra time and Ferguson also insisted his side should have been awarded a penalty in that incident.

But in the end he insisted fatigue caught up with United's star performers, including footballer of the year Cristiano Ronaldo.

Ferguson said: "You can't do much about it when they score as late as that. My players were too tired to launch a challenge.

"I didn't think we deserved to win or lose it. It was a game of stalemate and the pitch was slow.

"We had two or three players who looked tired from the first half. We looked jaded. It has been an exhausting season with a lot of matches and that is understandable.

"Cristiano looked tired today but he's a had a long season."

Ferguson did not blame the assistant linesman for the incident in which Giggs collided with Chelsea goalkeeper Petr Cech and the ball appeared to cross the line.

Instead he insisted United should have had a penalty for an earlier foul by Chelsea defender Michael Essien in the same incident.

Ferguson said: "It was a penalty kick although I don't think the linesman was in a position to see clearly if the ball was over the line. The referee (Steve Bennett) should have seen the Essien foul on Giggs.

"The fact that it was over the line makes it worse for us, but I don't think the linesman could have seen it."

The United manager also claimed pre-match mind games from Chelsea boss Jose Mourinho could have influenced referee Steve Bennett.

Ferguson said: "He puts referees under pressure every big game. He talks about referees. There are 22 players out there and he's talking about the referee all week.

"Maybe it worked for him today, actually. I was disappointed in the referee. An FA Cup final. I expected better."

Ferguson, however, did concede that the game had been won by a "fantastic" player in Drogba.

"He took the goal very well," said Ferguson. "He was aggressive, although we had contained his threat until that moment. He kept Chelsea's season alive though. He kept producing goals so they could stay within reach."

Ferguson admitted he would be looking to improve his squad for next season but insisted golden oldies such as Ryan Giggs and Paul Scholes were still integral to his plans.

"I don't see any depreciating in the standards of Giggs and Scholes," said Ferguson.

"They produced some great moments today and I don't have any concerns in that respect.

"It is important to improve ourselves though because there is no point standing still in life."