It's been a tough week for Manchester City. The Sky Blues lost 3-0 to the Red in the first leg and were beaten by rivals United in the Premier League.
But Pep Guardiola says City can beat Liverpool in their Champions League quarter finals.
The City manager says they need to bring their A Game, meaning they have to put on a perfect performance in order to stand any chance against Jurgen Klopps side.
"In football, in all the sports, basketball, it can happen, the Spaniard said. "So, all we can do is know we are going to try and we will see. Of course, we don't have to think about how many goals you have to score. We have to try to score the first."
Liverpool will be hoping that forward Mohamed Saleh, who has a groin injury, will be fit to play. The Egyptian has scored eight times in the Champions League since last June.
Roma will see the return of midfielder Radja Naibggolan and forward Cengiz Under, both injured for the first leg against Barcelona, but winger Diego Perotti is still sidelined with a calf problem.
"I think this match against Barcelona must be tackled with the best players, said Roma manager Eusebio di Francesco. "Right now this is the most important game for us and then we will think about the derby [against SS Lazio]."
"Tomorrow is an opportunity to show that we deserve and want to do something important."
Barcelona head to Italy with a three-goal cushion after beating Roma 4-1 in the first leg a Nou Camp.
The Catalans will be without Sergi Samper and Lucas Digne - while Sergio Busquets is an injury doubt.