Jordan Henderson is suffering from a knee ligament sprain.
The Reds skipper suffered a knee ligament sprain in the 1-1 draw at Borussia Dortmund in early April and was ruled out for up to eight weeks, all-but ending his season there and then.
His place at the European Championships with England was also placed into doubt - Will Roy Hodgson risk taking a player who wouldn’t have featured for two months leading up to the tournament?
Despite the fears, Klopp has told reporters that Henderson’s recovery progress is going well and suggests he will be in good shape to make the England squad this summer.
"Hendo in a good way for England, not sure about for Liverpool. Not on pitch yet," Klopp told Sky Sports ahead of Liverpool's Europa League semi-final second leg against Villarreal.
A fully-fit Henderson would undoubtedly be on the plane to France this summer, yet Hodgson has some key decisions to make with players such as Jack Wilshere also returning from a long injury layoff.
Ligament injuries take time to heal, and spending a lengthy period on the side-lines will naturally affect the overall fitness of the player in question - even more so at the end of a season.
Henderson was a key figure for Liverpool during their superb run of form leading up to his injury, and should he not make it this summer, he will no doubt be a big loss to England.