Jurgen Klopp believes the squad needs more endurance work ahead of the new season

Liverpool manager Jurgen Klopp says his players are at different fitness levels ahead of the new season and still have plenty of work to do.

The Reds play their final pre-season game against Torino at Anfield on Tuesday with Dejan Lovren's return this week meaning Klopp has his full squad together for the first time this summer.

There are just five days to go until Liverpool's Premier League opener against West Ham live on Sky Sports and Klopp is concerned that his side are not quite ready.

He told the club's website: "We need to get back the freshness, for one thing, and the other thing we still need to work on is endurance. The boys are not all on the same level, you can see that.

Liverpool, who are widely tipped to challenge for the title having spent £160m in the transfer window, have an eight-day gap before their second game at Crystal Palace on August 20, also live on Sky Sports, and Klopp feels that may be another problem.

"We need to play the first game somehow," he added. "Then we have another eight days because we play on Sunday and Monday. That is another pre-season week, I cannot change that. That's the challenge we have now.

1:35 'Liverpool have addressed problems' 'Liverpool have addressed problems'

"First of all, we have to make sure we have a good team for Tuesday and then for Sunday, then we have to prepare the next one. There's still a lot of work to do."

Liverpool are having no problem scoring goals in the build-up to the new campaign.

Saturday's 5-0 win over Napoli at Anfield came a week after they put four past Manchester United in the International Champions Cup.

Alisson kept a clean sheet on his Liverpool debut against Napoli

"I saw a lot of things (against Napoli) we were good in," Klopp went on. "I saw a lot of things we have to improve - not we should, we have to improve.

"In different moments we lost our compact formation when they played football. 5-0 sounds really clear and it is clear, but we all saw in the first half they had a lot of moments where they were in our box.

"Being in our box three times alone in front of the goalkeeper should not happen. It was only because of the formation, we were not compact enough in these situations."