The 18-year-old has been a regular in Brendan Rodgers' staring XI this season, with his performances earning a call-up to the England squad for the recent friendly against Sweden.
Sunday's game will be the first time Sterling plays United at Old Trafford, the team the Jamaican-born teenager admits to following when he first moved to Britain.
"I need to keep that quiet," he said. "But when you start playing for a team, you immediately start supporting them because you want to do your best for your team and you always want them to do well.
"The older boys say that Manchester United is one of the hardest places to go. The pitch is massive and in the last 10 minutes they say it gets even bigger.
"Hopefully we can go there, do our best and come out with a result even though it's going to be very, very hard -- a real test.
"The atmosphere in the dressing room is brilliant. We've got (Steven) Gerrard and (Jamie) Carragher, they're real characters. They're going to make us know what sort of game it is, what it's like and get us ready for it.
"They've been on us all week, telling how important it is. To have people around like that is brilliant. They've been around for so long.
"They love to have a laugh, good personalities and you need those characters in the dressing room."
And with Liverpool currently in eighth, Sterling is hopeful a positive result at Old Trafford can kickstart their season.
"I think we should be doing better," he added. "We'd like to be higher in the table.
"The manager has bright ideas, he's a good manager.
"We didn't start too well, but we're improving all the time and we're going to kick on in 2013. It's going to be our year.
"The manager has got his plans, it's really coming together now. It will be a big 2013 for us. Daniel Sturridge has come in, he's a real player."
Liverpool are seeking their first win at Old Trafford since the 4-1 victory of March 2009, but manager Brendan Rodgers says he is not a "magician" as he tries to rebuild a club who have spent pretty disastrously in the past few years. "I will be able to improve players -- that is my work and I have confidence in that," he said.
"If I look at (my) first six months, there have been improvements in a lot of the players. I will be able to take them and wring everything that I possibly can out of them.
"But the bottom line is about talent. If you don't initially have that then it can be difficult.
"You look at Jordan Henderson, Stewart Downing and Jose Enrique since the start of the season and we have added value back to them. Absolutely.
"That is something we will look to do because we don't have the resources of the top clubs who are out there paying big money. We have to find the difference through the coaching.
"We will always be governed by budget, always be governed by restrictions on certain things within the club because if you haven't got the money you can't spend it."
Though Sunday's game is essentially a match-up between the two best players in the Premier League this season -- Robin van Persie and Luis Suarez -- Liverpool have finally become less dependent on their talisman, with nine different scorers plus Suarez since the start of December.
"I never worried about it," Rodgers said. "I always said it has to be more than Luis Suarez who scores. As the season has gone on people have improved and developed as players and (in) performance level and that has helped the team."