In a dominant performance from Brendan Rodgers' side, Rooney couldn't make a significant impact on the game.
When he was on the ball, he was uncharacteristically off-target with various passes as well as losing the ball on a couple of occasions thanks to heavy touches.
That being said, the Englishman showed his creative flair on a couple of occasions as well as forcing a good save from Simon Mignolet for United's best chance just before half-time.
And there was certainly no lack of effort from the 28-year-old. But with Liverpool so clearly superior, Rooney struggled to really get in the game.
Speaking before the match, Rooney said he and Robin van Persie could do more to contribute, as reported by Gary Jones in the Daily Star:
I think we are doing alright. Obviously, we can do better and if we are not at the top of the league then that will get looked at and we understand that.
Personally, we can score more goals and we know we can. We are working hard to do that, we have to keep going and hopefully that will come.
Unfortunately for the former Everton man, he and his strike partner Van Persie could not get on the score sheet.
There were opportunities. Rooney played the Dutchman into good positions on a few occasions, but Van Persie was not clinical enough with his finishing.
David Moyes will hope that his strikers can do more when they host Olympiakos on Wednesday in the last-16 second leg at Old Trafford.
Already 2-0 down in the tie because of a poor performance in the first leg, United will have to score at least three if they want to advance to the quarter-finals.
With the loss to Liverpool extinguishing any hope of making the top four for the Red Devils, they will have to win the Champions League to qualify for next season's competition.
And Rooney will be key if United want to perform a turnaround against the Greek champions.
There were signs of Rooney's usual brilliance against Liverpool, but the Reds' dominance meant he was often chasing the game. On Wednesday, he will need to get on the ball more often if he wants to inspire a comeback from United.
Following the match, Rooney spoke on the crushing defeat (via Stephen Darwin of Goal.com):
And Rooney, who endured a frustrating afternoon where he saw little of the ball, confessed that the loss at Old Trafford was one of the worst he's suffered during his entire career.
He told MUTV when asked about the mood in the camp after the defeat to their rivals: "It's a nightmare. It's one of the worst days I've ever had in football."
With the attacking flair of Rooney, Van Persie, Juan Mata and Adnan Januzaj, it seems extraordinary that Moyes' side could only register one shot on target against Liverpool.
United must beat Olympiakos to avoid going into a downward spiral, which could see their season ending in total failure.
Rooney's performance will be key going forward but he needs assistance from his team-mates so that United can dominate matches as they used to.