"If you see the replay on TV you can see he kicked me in the foot and that is why I am limping," said Ronaldo. "But it is the ref's decision and we have to respect it. It was not the right decision but with the pressures of the game, it is so quick. He gave me a yellow card and I don't know why."
Related ArticlesRonaldo's reputation earns yellow
Man United win Carling Cup
Papers: Liverpool's five goal thriller 'not enough' for Benitez
Carling Cup man marking: Manchester United
Carling Cup man marking: Tottenham Hotspur
As it happened: Man United beat Spurs on penalties
Having missed a penalty in the Champions League final last May, Ronaldo shot to the right as United won the shoot-out 4-1.
"Penalties are a lottery, it is always important to score and I chose a side to put the ball," he said. "I know after Moscow the keeper was probably thinking I was going to put the ball there again, but this time I change. It I great for me and great for the team."
However, he played down the possibility of Manchester United winning an unprecedented clean sweep of major trophies.
"It is quite difficult," said Ronaldo. "We are going game from game. We win this cup and now we are top of the Premier League and in the Champions League and the FA Cup.
"Manchester always have the opportunity to win everything but we need to put our feet down and go game to game, but we have a good chance to win the same as last season. We don't have much time to celebrate."
Tottenham manager Harry Redknapp believes that United can realistically hope to go on and win the FA Cup, Champions League and Premier League.
"They wanted to win as badly as we did," said Redknapp. "When there's a trophy to be won, Alex wants to win. He's not going to play a load of kids and, if they get beat, say 'unlucky'.
They've got a big chance of winning the lot. They're the team to beat, certainly, and have a fantastic squad. The league's going their way, for sure. You wouldn't bet against them to win the Champions League."
Redknapp was happy with his own team's performance and praised Jamie O'Hara for having the courage to take Tottenham's first penalty.
"He's got a great left foot and was the first to volunteer for one," he said. "He fancied one. Unfortunately, the keeper made a good save. I'm pleased I got him on today. He left here in tears last year. He feels for the club, is part of the club.
"I've been impressed with him as a player and a person, a terrific fella and great lad, and I was pleased that he played a part.
"I thought we were super. It was a great performance and it came down to a lottery in the end. I have to be honest, we were not that confident with our penalty takers really and you looked over there and they had very confident penalty takers.
"But, overall, they couldn't beat us in 90 minutes plus extra-time so we didn't deserve to lose and I thought we were fantastic. There's injuries, there's fatigue, we've spent all our resources. Dawson's cramped up.
"Ledley didn't cramp or anything, unbelievable. How he got through it, I don't know. For him to play like that again is unbelievable. Dawson's the best chance of playing on Wednesday.
"They've decided in their wisdom to fit in another big game on Saturday because we haven't been playing enough. Aston Villa go off to Dubai with a nice free weekend. We tried to rearrange it [the Sunderland game], but they said it should be played on Saturday. There were loads of spare mid-weeks we could have played, but they try to get the fixtures in as quickly as possible.
"We'll be ok. We'll lift them. We'll have one or two who didn't play today who will be available. Aaron Lennon seized up with cramp, but he was terrific."