England medical staff are said to fear that Tottenham striker Harry Kane is at risk of not being fully fit at the World Cup in Russia this summer after rushing his comeback from ankle ligament injury he suffered in March.
The problem only forced the 24-year-old to miss his club's FA Cup quarter final win over Swansea and ruled him out of England duty for the international friendlies against Netherlands and Italy.
A report from The Times explains that England have cause for concern after an expected six-week layoff was reduced to just three. Kane has subsequently played in six games, scoring three goals, but performance indicators such as sprints and shots have been down on his usual.
With 27 Premier League goals to his name, his determination to catch Liverpool's Mohamed Salah and win a third consecutive Golden Boot could well be proving problematic as he is potentially putting too much of a demand and strain on himself.
Since making his comeback as a substitute against Chelsea on 1st April, Kane has barely missed a moment, with a late withdrawal against Brighton two weeks ago the only time that he hasn't completed a full 90 minutes.
Despite seeing his club career take off in recent years, a strong summer tournament is still something that is missing for Kane. He struggled at the Under-21 European Championship in 2015 after a breakout season for Spurs, and then later at Euro 2016 at senior level.
England, who are already without Alex Oxlade-Chamberlain for the World Cup, have been severely hindered in the past by star players being short of full fitness.
David Beckham wasn't fully fit at the 2002 World Cup after suffering a broken metatarsal only a few weeks earlier and it showed, especially in the quarter final against eventual champions Brazil.
Wayne Rooney was recovering from a metatarsal problem in 2006 and was also below par at the tournament - his frustration later boiled over in the quarter final against Portugal.
Kane fills a similarly talismanic role for the current Three Lions and it is vital that he is firing on all cylinders if England are to make any sort of impact in Russia. If he is struggling for fitness, manager Gareth Southgate may have some tough decisions to make.