Ferdinand continued a somewhat unsporting week by shoving Torres in the off-the-ball incident during the 2-2 draw.
The centre back, touted for a recall to Roy Hodgson's England squad, went in for a challenge with Torres and after the pair had got up, barged him with his forearm and kicked his achilles while the referee was looking the other way.
The Chelsea striker fell to the ground in a heap and Ferdinand then dragged the Spaniard back to his feet.
On Tuesday night Ferdinand was seen sarcastically clapping in referee Cuneyt Cakir's face in the aftermath of United's 2-1 defeat by Real Madrid.
Cakir had controversially sent off Nani during the game and the furious Ferdinand made his feelings clear at the final whistle.
He has avoided censure from UEFA over the incident and the club also were not punished for not fulfilling their post-match media obligations.
Sir Alex Ferguson refused to speak after the Madrid game and his players were also prevented from speaking.
Ferdinand and the Scot spoke to MUTV last night after the Chelsea match.
The 34-year-old centre back said: 'We gave them the impetus to claw their way back into the game. We played some great football at times but were so careless at times. If you are careless you are going to get punished. That was the case.
'But we are still in the cup. Wembley is waiting for one of us to go through and hopefully it is us.
'We go to Stamford Bridge for the replay with confidence. We have the tools. We have been there before this season and done well and with the squad we have we don't fear going anywhere.'
Ferguson said his team paid for their efforts against Real in midweek.
'We're lucky to be in the Cup. We just ran out of legs and Chelsea were far the better team in the second half,' he said.
'But I can't be critical of my side because the running they had to do on Tuesday night, against a really top side in Real Madrid, had its bearing on today's result, no doubt about that.
'The two full backs, Rafael and Patrice (Evra), are knackered and the two central midfielders tired badly. We kept giving the ball away and it made it a long day for us, going from one penalty box and back to our own.'
Ramires and Eden Hazard levelled the game for Chelsea following early goals by Javier Hernandez and Wayne Rooney. United lost Nani with a hamstring problem at the end of the first half but Ferguson said the injury was not 'too serious'.
Meanwhile, Chelsea boss Rafael Benitez accused Ferguson of snubbing his attempt to shake hands before the start of the game.
Benitez claimed he was waiting to shake hands with the Manchester United boss but Ferguson walked past him without doing so.
The Chelsea interim manager said: 'I was waiting at the beginning. It's up to him, I was in the way waiting.'
Asked why Ferguson might have done so, Benitez added: 'Ask him - if you are brave enough ask him. It was his decision. I was ready and waiting. I have some education because I know a lot of people are watching so I know what I have to do.'
Benitez said he had not seen the incident involving Ferdinand and Torres.
He added: 'I haven't. Fernando mentioned it - but you can see the replay.'
Idiotic: Ferdinand sarcastically clapped in Cuneyt Cakir's face on Tuesday