Luis Suarez has said Liverpool belong in the Champions League and added the future is bright at his former club under the management of Jurgen Klopp.

In Klopp's first full season in charge on Merseyside, Liverpool achieved a fourth-placed finish in the Premier League, meaning they are one playoff round away from a place in next term's group stages of Europe's premier club competition.

Suarez is considered one of the best players to have ever played for Liverpool, scoring 82 goals in 133 appearances during his three-and-a-half-season stay at Anfield before a £75 million move to Barcelona in the summer of 2014.

"Liverpool always have to be competing in the Champions League," Suarez told the club's official website. "I think the new manager, Klopp, needed a bit of time, because he came in during the previous season, but he's had a fantastic [first full] campaign.

"I think that things will go even better next season because he's a quality coach and he has a lot of players who can make the difference. Absolutely, Liverpool is a club that should always be involved in the Champions League."

Luis Suarez scored 82 goals in 133 appearances for Liverpool. Alex Livesey/Getty Images

Meanwhile, Liverpool have confirmed both Philippe Coutinho and Adam Lallana will report back for preseason training on Tuesday.

Emre Can is the only Liverpool player yet to start preparations for the 2017-18 campaign, having been given time off after helping Germany win the Confederations Cup.

Lucas Leiva says Klopp's summer work is as "intense" as he has ever undergone in his career, but added it gets the squad in the right shape physically prior to the start of the season.

Liverpool have been training at Melwood since last week ahead of their first preseason friendly against Tranmere Rovers on Wednesday night.

"They try to test everything -- power, balance, stamina, everything. It's good," Lucas said. "We had a plan to do during the break; it wasn't too hard, just to make sure we got here in good shape to start preseason because that's what preseason is about: fitness and getting better.

"It builds up. It's very intense, like it should be. But when you have experience you know how to manage it. I've missed the ball a lot. I haven't played football for my whole holiday. So it will be good to start with the ball and get together again and get the movement going. Hopefully by August we'll all be very, very fit."