The two great rivals will meet in European competition for the first time this week when Anfield plays host to the first leg of their Europa League last-16 tie.
Both sides face an uphill battle to break into the top four in the final two months of the Premier League season, meaning victory in Europe’s secondary tournament represents their best chance of securing a Champions League spot for next term.
And Garcia, who won the Champions League and European Super Cup during his three-year spell on Merseyside, has urged his former club to embrace the occasion against United in order to keep their hopes of reaching the final in Basel alive.
“It’s the Clasico of England, I think,” Garcia said.
“After a disappointing season in the Premier League, to have that game, win that game and go through would be fantastic for the club, for the supporters and for the players.
“It’s a fantastic game against Manchester United. I think it’s one of the games that the supporters are going to look forward to.
“It’s a fantastic chance to get in the Champions League next year and it’s probably the only one because the fourth position in the league is very far away.
“Winning that competition can give you that so I think the club knows, the players know and they’re going to give everything.
“It’s not easy, we saw in the last game it was very tight and it’s going to be tighter as Liverpool go through, but it’s a competition that Liverpool can win.”
Garcia feels getting back into the Champions League is essential to Liverpool’s transfer plans at the end of the season, but believes the return to form and fitness of Daniel Sturridge, Philippe Coutinho and Roberto Firmino could prove the key to their chances.
“We’re in that moment when you don’t know if they’re going to reach the Champions League, it’s getting far away,” Garcia said, with Liverpool six points behind fourth-placed Manchester City.
“Chelsea is recovering and they’re going to be another contender to fight for those four or six positions.
“Liverpool needs to be there for next year. I think it’s very important because the top players want to play in the Champions League and if you are not there, they don’t think about coming. It’s difficult of course, but we knew that from the very beginning.
“Now Sturridge is getting fitter, Coutinho came back from an injury and Firmino has been scoring goals. I think the team is looking better and hopefully they can get those two or three wins in a row and close the gap on fourth position.”
Despite their inconsistent league form, Garcia believes Jurgen Klopp’s impact on the team is beginning to show in the intensity with which they play.
“It was a big change when the new manager arrived,” the 37-year-old, now at A-League side Central Coast Mariners, said.
“The team looked different, approached the games different, started to get some good results, but right now the consistency needed in the Premier League isn’t arriving.
“I think what you can see is the intensity of the games that Liverpool have, the running, the closing, the pressing. Every time you see a player lose the ball, they have three players around to try to press and I think that’s something he’s changed.”