Scot praises the performance of Danny Welbeck and Co. after the victory over Spurs, and admits that the return of Javier Hernandez has brought along a selection problem
The Red Devils took the lead in the second half through Danny Welbeck, before further goals from Anderson and Wayne Rooney secured a convincing win.
Now the Scot has hailed the likes of Tom Cleverley, Phil Jones, Chris Smalling and Danny Welbeck for the part they played in the match.
"It tells you we still believe in young players. All the fans appreciate that," Sir Alex said. "This is what the club is all about. We have always had confidence to play young players and this group has such fantastic ability it forces you to play them really."
With Welbeck putting in impressive early-season performances and Javier Hernandez having returned to fitness following a concussion, the presence of Dimitar Berbatov and Michael Owen has given the boss a selection headache.
"If you look at Berbatov, Michael Owen, Chicharito [Hernandez] and Wayne Rooney we have different qualities," he said. "You have to utilise all that and make changes as best you can. But the horrible part for me now is, with Chicharito back, what do we do? It is going to be a big problem."
Sir Alex added: "He [Welbeck] has always had that ability but he has made slow progress because when he was growing up he had a knee-growth problem. It was a situation where we knew we had to wait for him. We put him on loan to Sunderland [last season] and that is when he became a man. He has grown up, and the lad has a great future."
The 69-year-old was also happy with David de Gea having kept his first competitive clean sheet for United, and also praised Chris Smalling, who has played at right-back so far this season.
Sir Alex said: "David was very confident. He was excellent. He got a bit slack towards the end of the game but other than that he was very confident."
"He [Smalling] had a marvellous season last year and he is showing more maturity," the boss added. "He has done a great job at right-back. You'd think he'd played there all his life. We are pleased with all these players. They have all done well tonight and you cannot criticise any of them."