Daniel Sturridge
Daniel Sturridge could re-establish himself as a key player for Liverpool in 2017-18 Victor Fraile/Getty Images

Liverpool midfielder Adam Lallana has joined manager Jurgen Klopp in waxing lyrical regarding Daniel Sturridge's impressive summer progression, suggesting that a return to form for the injury-plagued England striker in 2017-18 would be like having "two new signings".

Last season was certainly one to forget for Sturridge, who scored just seven goals across all competitions after battling further calf and hip problems. He was even linked with a potential move to West Ham United and reportedly rejected a lucrative switch to Chinese Super League outfit Beijing Guoan in order to remain at Anfield.

Klopp has previously expressed his frustration at not having Sturridge available on a frequent basis, although stressed earlier this month that the former Manchester City and Chelsea frontman was in the best physical shape of his tenure to date.

He later claimed that the player was "reaching for the next level" and hinted there would be plenty of opportunities for him to play this term as Liverpool look to book their place in the group stages of the Champions League.

Sturridge has featured in all five of Liverpool's pre-season friendlies so far, starting matches against Tranmere Rovers and Crystal Palace and appearing as a substitute against Wigan Athletic, Leicester City and in the 3-0 win over Hertha Berlin on Saturday [29 July].

But whether the England international's new-found fitness will deter Klopp from adding to attack during the remainder of the summer remains to be keen. Monaco's teenage sensation Kylian Mbappe has been linked with Liverpool during the transfer window but a move worth a reported €180m to either Real Madrid or Manchester City appears more likely.

While he has yet to open his scoring account ahead of the Audi Cup tournament in Munich, Lallana believes his club and international teammate can register a huge impact providing he manages to stay fit.

"Listen, Studge has been absolutely brilliant in pre-season so far," he was quoted as saying by multiple outlets, including the Liverpool Echo. "He is looking really sharp and to have him firing on all cylinders would be like having two new signings if we can keep on the pitch and get him scoring goals.

"He is a world class player. He has come back from the summer looking absolutely brilliant, so fit. He is going to be a massive player for us this season. I can feel it. You couldn't put a price on him. Every footballer gets injuries – Jordan [Henderson] has had a tough couple of years. We all have to deal with it at some stage in our career."

Klopp fielded attacking midfielder Roberto Firmino as the central forward in a front three for much of last season and the fact that the Brazilian switched to the number nine shirt following Mohamed Salah's arrival from AS Roma suggests he is likely to so again this time around.

The additions of Salah and England Under-20 World Cup star Dominic Solanke, who impressed again at Berlin's Olympiastadion, plus the return to fitness of Sadio Mane gives Klopp a wealth of attacking options even with doubts surrounding the future of Barcelona target Philippe Coutinho.

Sturridge seems likely to compete with Divock Origi, Solanke and the returning Danny Ings for minutes behind Firmino.