Oxlade-Chamberlain was involved in a challenge with Roma's Aleksandar Kolarov and underwent lengthy treatment on the pitch before being carried back to the dressing room on a stretcher, and Georginio Wijnaldum came on in his place.

Klopp said "it looks like" the 24-year-old will not be able to return for Liverpool before their potential Champions League final on May 26, while Oxlade-Chamberlain could also be a major doubt for England this summer with the World Cup less than two months away.

"We don't know it exactly, but all the medical department is quite concerned without a scan," Klopp told a news conference. "Then you can imagine that it's difficult. The season is not that long anymore.

"It doesn't look good. I'm a very positive person and I hope that it only feels bad but is not that bad. We will see."

Roma were able to cut Liverpool's 5-0 lead to a three-goal deficit late on, but Klopp said after the game that Oxlade-Chamberlain's injury was the "biggest blow for the mood in the dressing room."

"The biggest problem that we have today 100 percent is that we lost Oxlade-Chamberlain, who played brilliant as long he was in," Klopp said in a postgame television interview. "Thank God Gini [Wijnaldum] played as well, fantastic.

"But that's a serious injury and with our squad situation at the moment it's of course not really cool."

Klopp bemoaned the number of setbacks that have struck Liverpool this season, as injuries to Emre Can, Adam Lallana, Joel Matip and Nathaniel Clyne -- the last of whom returned to the bench on Tuesday -- have limited the Reds' depth.

"We all know, the best thing, if you go direct to final, semifinals and have important games in [the domestic] league you need a full squad," Klopp said. "We have pretty much the opposite of a full squad at the moment.

"But I said it a few times, obviously the Liverpool way is always a little bit harder. So we have to find solutions, we need to be creative, and that's what we try to be."