Liverpool forward Xherdan Shaqiri is facing a battle to be ready for the start of the season after manager Jurgen Klopp revealed he would be sidelined for "a while".

Shaqiri is still carrying a calf injury sustained on international duty with Switzerland in their Nations League defeat to England on June 9.

The former Stoke player returned to the club's Melwood training ground this week and assessment by medical staff has given Klopp a headache as he steps up his pre-season preparations.

"Shaq is still injured from the national team and it will take a while until he is in again," Klopp told liverpoolfc.com.

"He has a tear in his calf, so he will not be involved for a while."

The 27-year-old, a £13million buy last summer, has plenty to prove to Klopp after fading in the second half of their Champions League-winning campaign.

Champions League hero Divock Origi – now in the final year of his contract with a new deal offered but not yet signed – is the manager's only senior forward after the departure of Daniel Sturridge.

Youngster Rhian Brewster will be part of the first-team squad full-time this season after recovering from serious ankle and knee injuries while Harry Wilson, who impressed on loan at Derby, will get a chance in pre-season.