Liverpool boss Jurgen Klopp can sympathize with with Jose Mourinho's complaints regarding the crunched fixture schedule in England.

Mourinho's Manchester United advanced past Rostov in the Europa League round of 16 on Thursday and the Portuguese manager tore into the schedule-makers afterward, complaining of start times and calling them one of United's "enemies " this season.

Klopp was taken aback by the English schedule upon taking the Anfield reins after Brendan Rodgers was sacked, and picked up the torch for Mourinho while speaking to English newspapers on Friday.

"I heard what Jose Mourinho said and what the pundits think about it," Klopp said.

"Last season we had the same experience. It was really hard. We played Villarreal and then Swansea at 12.

"If they want to help, you cannot do that, you should not do that.

"I know it is contracted, but that's only 12 p.m. or 4 p.m.? Don't play then.

Jurgen Klopp backed Jose Mourinho on Friday. Angel Martinez/Real Madrid via Getty Images

"Don't make it more difficult than it should be. I really understand. We thought the same last season.

"We thought it was really hard. That was an experience. This year we could not use it but next year hopefully we can use it. That's how the job is."

Klopp's men will face Manchester City in a battle between the Premier League's No. 3 and 4 teams.

The German boss urged his side not to hold back against Pep Guardiola's attack-minded team.

"For me City is the most difficult team to play," said Klopp.

"I know their image at this moment in this country is a little bit different. I've heard about Pep Guardiola's style and all that stuff but it is real football and it is difficult to defend against them and a lot of teams have failed already.

"If you are passive against City you have no chance. You have to be active and to be active you need to brave.

"Monaco couldn't do it for two halves: in the first half they were good, second half it was chance after chance [for City] and we cannot hope Aguero misses these chances again. In the first half it was really brave of Monaco.

"If you can win the ball there are maybe a few spaces you can use. We know what we have to do there. We will try everything to do the right things and then it could be a fantastic game to watch."