The Merseyside outfit head into the game having earned plenty of praise for their performance at Anfield in the first leg last week as Jurgen Klopp’s men took a 2-0 lead thanks to goals from Daniel Sturridge and Roberto Firmino.
Liverpool know that scoring a goal at Old Trafford on Thursday night would present United with a significant uphill task as they bid to knock their bitter rivals out of Europe’s second tier club competition.
However, former Liverpool star Fowler is confident that Klopp’s side have what it takes to progress to the last eight.
Speaking to the Liverpool Echo, Fowler said: “Our recent record at Old Trafford isn’t great but the players should have taken great confidence from the first leg.
“Manchester United can’t play as badly as they did at Anfield so we’ll have to be on our toes.
“But a Liverpool team should never bow to anyone. We need to be positive and I am quietly confident we can do the job.”
He added: “Liverpool are in a great position but I don’t think it’s over yet.
“If someone had said before the tie that we would have a 2-0 lead to take to Old Trafford then we all would have taken it.
“But the disappointing thing about the first leg was that we didn’t score more goals. The tie really should have been put to bed.”
Liverpool had a free weekend to prepare for Thursday’s game, while Manchester United came from a goal down to earn a 1-1 draw against West Ham and force an FA Cup quarter-final replay.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news