London - Liverpool manager Jurgen Klopp says Manchester United have "unbelievable quality" despite their struggles this season, playing down his own team's growing injury problems ahead of Sunday's Premier League clash.

Liverpool are top of the Premier League heading into the weekend fixtures, 16 points ahead of Jose Mourinho's side, but the Klopp is taking nothing for granted.

"I was never interested in the points of Manchester United and I am not today," he said on Friday.

"I am aware of the criticism and stuff but when we analyse them and switch off the sound there is a lot of quality.

"There is speed, technique, physical strength, pretty much everything. They still have (David) de Gea in goal, unbelievable. They have strikers they can switch between (Marcus) Rashford, (Romelu) Lukaku, (Jesse) Lingard, (Anthony) Martial, unbelievable quality."

Mourinho has been wrestling with the problem of how to get the best out of midfielder Paul Pogba, who has not been in the starting line-up for the past two Premier League matches.

Klopp was asked whether he thought United were better with or without the World Cup winner but said he would not comment beyond calling him a "world-class player".

He said he is unlikely to make a move during the January transfer window after insisting his mounting injury problems in defence are not a crisis.

Right-back Trent Alexander-Arnold (foot) and Joel Matip (broken collarbone) this week joined Joe Gomez (broken leg) on the injury list.

Midfielder James Milner played at right-back recently and Nathaniel Clyne has returned to fitness but has barely featured since the beginning of last season.

Klopp admits he may have to get creative but that is unlikely to involve spending in January.

"A crisis is if you feel it is a crisis," he said. "With Trent, it's not as serious as with the other two boys, but of course it's not top-class news, that's clear."

A back problem restricted Clyne to just five appearances in the final few weeks of last season and his injury issues have continued into the current campaign but his return to full training is timely.

"Clyne is a very experienced player," said Klopp. "Is it perfect? No. But is he experienced enough to do it? Yes, 100 percent.

"We have other options so we will not push Clyney after not the longest spell of training.

"As long as we have options everything is fine. If we don't have the obvious option any more then we need to be creative."