Champions League - Ancelotti hints at Torres mistake
And the Spaniard extended that run with another miserable 45 minutes before he was hauled off at half-time.
Torres was replaced by Didier Drogba at the break and it was the Ivorian who gave Chelsea a glimmer of hope when he equalised on the night with 13 minutes remaining.
But that effort was almost immediately cancelled out as Park Ji-sung restored the lead given to United by Javier Hernandez just before half-time.
With Chelsea down to 10 men following the dismissal of Ramires for a second bookable offence on 71 minutes, there was no way back for Ancelotti's side, whose Champions League dream ended early once again.
Asked if his gamble of playing Torres instead of Drogba had backfired, Ancelotti said: "Maybe. Could be. I told you a lot of times this season I wanted to start with Fernando for this kind of game, these type of tactics.
"Didier played well in the second half. I wanted to put more pressure up front because we needed to score. Didier was fresh and he could use his power up front. This was the reason I took out Fernando."
United boss Alex Ferguson believed Ancelotti's inclusion of Torres from the start was down to the striker's price tag.
He said: "A lot of people thought Drogba would play. I thought having signed Torres for the money they did they had to play him.
"I wasn't 100 per cent sure but I couldn't see how they could leave Torres out.
"They had the opportunity to sign Torres and I don't think anyone would have turned it down.
"Everyone said at the time it was fantastic business. You can't criticise him (Ancelotti) for that, it was a good signing. It isn't working at the moment but he is a young man and there are other seasons ahead.
"Torres has played against us quite a few times and he had a little goal spell at Old Trafford and got a goal at Anfield but we've actually done all right against him.
"It's made out that he's tortured us. He's a good player but with (Nemanja) Vidic's experience and (Rio) Ferdinand's experience they should be able to handle the best players in the world. They are in that sphere of being top players themselves."
Ferguson singled out "incredible" old-timer Ryan Giggs for an outstanding game in the centre of midfield from where he set up Hernandez's 43rd-minute opener while adding that the Mexican had almost not started as he had toyed with a different line-up.
"We had two teams picked tonight and hopefully I picked the right one, I'm not sure I did pick the right one," Ferguson said.
"The other option is to play Park in that position and Wayne (Rooney) up top, leaving Chicha (Hernandez) out. That's where you get luck, Chicharito scores the first goal."
While the loud taunts from United fans to Ancelotti of "You're getting sacked in the morning" were possibly wide of the mark, the Italian is under pressure now his side's last realistic chance of silverware has vanished.
"I'm not concerned," he said when asked if he was worried about his job given owner Roman Abramovich, who was watching from the stands, has been quick to show the exit to previous managers who finish a season without a trophy.
"I have to work, I have to try to do my best. It is not my decision to stay or not stay," said Ancelotti.