United and Chelsea were paired in Europe's elite competition for the first time since that rainy night in Moscow three years ago, when Alex Ferguson's side won 6-5 on spotkicks following a 1-1 draw after extra time.
The scars of that agonizing defeat still haven't healed at the London club, which is yet to win the Champions League.
"If our players think about the game in Moscow, obviously they are not happy," Ancelotti said. "John Terry (who missed a penalty in the shootout) is not happy about what he lost in that game, other players are not happy also and that could be a good motivation.
"This could be a destiny. It could be the real time that Chelsea do something in the Champions League."
Chelsea will get even more satisfaction from knocking out United, given that Ferguson's men are on the verge of ousting them as English champions.
United is top of the Premier League, 11 points ahead of third-place Chelsea, which has a game in hand but is unlikely to bridge the gap in the final seven weeks of the season.
The Blues are, however, showing improved form after their midseason slump and hasn't lost in two months. During that run, Chelsea defeated United 2-1 at home in the league to extend its impressive recent record against the northwest side, which has won only three of their last 19 competitive meetings.
"Our record against United is very good, especially at home, and we go into the game thinking it could be an advantage," Chelsea goalkeeper Petr Cech said. "Playing at home, if we get a good result, we will be in a good position." United, a three-time European champion, is still smarting from its defeat at Stamford Bridge on March 1, when Chelsea rallied from a goal behind at halftime thanks to center back David Luiz and midfielder Frank Lampard.
Wednesday's first leg promises to be just as close.
"They have an edge because they had good (results) against us," said United captain Nemanja Vidic, whose side hasn't won away against Chelsea in nine years. "But this is the Champions League. The name of the game on Wednesday is to get an away goal." Spain striker Fernando Torres could return for the hosts after starting on the bench in Saturday's 1-1 draw at Stoke in the Premier League but Luiz, a fellow signing in the January transfer window, is ineligible.
United, coming into the game on the back of a 4-2 win at West Ham on the weekend, could welcome back defender Rio Ferdinand, who has been out since the start of February with a calf injury but trained on Tuesday.