Liverpool striker Daniel Sturridge faces a race against time to be fit for Liverpool's opening Premier League match at Arsenal, live on Sky Sports 1 HD from 3.30pm this Sunday.
The 26-year-old has been plagued by fitness problems since joining the Reds from Chelsea in January 2013, with the latest setback his 21st reported injury on Merseyside.
Klopp: No idea on Sturridge
Jurgen Klopp unsure Liverpool striker Daniel Sturridge will be fit for Arsenal
Sturridge made just 14 Premier League appearances for Liverpool last season and only 12 in the 2014/15 campaign and now Liverpool boss Jurgen Klopp says he has "no idea" whether he will be fit for their opening clash at the Emirates Stadium.
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With the help of Physio Room, we take a look at Sturridge's injury timeline as fears grow over another spell on the sidelines for the England international…
February-March 2013 - dead leg and minor knock (missed three games)
Sturridge made a superb start to life at Liverpool, scoring four goals in his first six appearances, but his first injury came just a few weeks after his arrival when he suffered a dead leg in a 2-2 draw with boyhood club Manchester City.
Sturridge missed games against West Brom and Zenit St Petersburg before returning for a 5-0 thrashing of Swansea, but a minor knock sidelined him again and he missed a 4-0 win over Wigan.
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May 2013 - ankle ligaments (missed no games)
Sturridge lasted just 33 minutes of England's friendly against the Republic of Ireland at Wembley. His injury was confirmed as ankle ligament damage, but he returned in time for pre-season and, fortunately for Liverpool, he didn't miss any domestic action.
September 2013 - thigh (missed no games)
The striker scored five goals in his first four Liverpool appearances of the 2013/14 season, but he missed England's games against Moldova and Ukraine due to a thigh problem. He recovered in time to face Swansea - and score - after the international break.
November 2013 to January 2014 - ankle ligaments (missed nine games)
Sturridge aggravated a thigh problem on England duty meaning he only started on the bench for a 3-3 draw with Everton on November 23, and in the aftermath of the game, he was ruled out for two months with ankle ligament damage, missing nine games.
April 2014 - hamstring (missed one game)
Sturridge went unscathed for four months as Liverpool's title charge gathered pace, but he limped off with a hamstring problem during their 3-2 win over Manchester City. He missed their 3-2 win over Norwich and was only fit enough for the bench in their infamous 2-0 defeat to Chelsea at Anfield.
July 2014 - hamstring (missed no games)
The 26-year-old had to return home from Liverpool's pre-season tour of the US after picking up a hamstring injury. Liverpool breathed a sigh of relief as he returned in time for the start of the season.
September 2014 to January 2015 - thigh and calf (missed 32 games)
Just three games into the season, serious injury struck again as Sturridge hurt his thigh in England training. He was expected to make his comeback in late October, but he suffered a calf problem before Liverpool's trip to QPR.
Then, another comeback was pushed back when he picked up another thigh problem before a 3-1 defeat to Crystal Palace on November 23. In the end, he didn't return to action until the last day of January.
April to September 2015 - hip (missed 14 games)
Sturridge's appearance in an FA Cup tie against Blackburn in April turned out to be his last of the season for the Reds, and a month later he went under the knife for an operation on his hip.
He missed 14 games for Liverpool in total, making his long-awaited return to the side in a 1-1 draw with Norwich on September 20.
October to November 2015 - knee and foot (missed nine games)
Just three games into his comeback, Sturridge was ruled out yet again as he picked up a knee injury ahead of Liverpool's trip to Tottenham on October 17. He was due to return to action against Bordeaux only to be sidelined by another injury blow. Eventually, he returned as a second-half substitute against Swansea on November 29.
December to February 2016 - hamstring (missed 16 games)
After his cameo against Swansea at Anfield, Liverpool fans were excited to see Sturridge's name in the starting line-up at Southampton the following week. And that excitement intensified when the England striker scored twice in a remarkable 6-1 Capital One Cup victory.
He was on the bench for Liverpool's Super Sunday clash at Newcastle on December 6, but tweaked his hamstring after coming on as a substitute in the second half. A scan later revealed he had suffered a strain, and he was sidelined for several weeks.
May to June 2016 - calf (missed two England friendly games)
After a strong finish to the season with six goals in nine games, including a sublime strike in the Reds Europa League final defeat to Sevilla, Sturridge looked to be finding his best form.
He then faced an anxious wait to learn England fate for the Euro 2016 squad after missing their first two warm-up games against Turkey and Australia because of a calf injury.
But after training with the rest of the squad at London Colney and then getting a 12 minute run out during England's final friendly against Portugal at Wembley, he proved to manager Roy Hodgson that he was ready for the Euros.
August 2016 to present - hip (missed Liverpool's final two pre-season matches)
After failing to make the starting line-up in England's opening 1-1 draw against Russia at Euro 2016, he finally made an impact by scoring a dramatic late winner against Wales in the second group game.
Sturridge failed to light the blue touchpaper against Slovakia and then Iceland in the last 16 as they dumped England out of the tournament.
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Now Jurgen Klopp is unsure if he will be able to call on the player for Liverpool's opening-day match at Arsenal after missing Liverpool's final two pre-season matches against Barcelona and Mainz with what the club described as a slight hip issue.