The 26-year-old signed for Fulham for £12 million in January but has made just a handful of appearances for the club, with injuries curtailing his impact on the Premier League.
Mitroglou has now suffered similar injury problems at this World Cup, not starting Greece's 3-0 defeat to Colombia, before having his recall to the side cut short against the Japanese.
Should the injury prove a serious one, it could present a potential stumbling block in Fulham's attempts to sell the striker, with Besiktas one of several clubs reportedly interested in taking him on loan with a view to a permanent deal.
The west London side have been linked with Australia striker Adam Taggart, as well as Leeds' Ross McCormack, so the need to offload Mitroglou's wages is a serious priority for the Cottagers.
But even if the 26-year-old's injury proves a short-term one, clubs may still be deterred from a man who has done very little to prove himself since moving from Olympiakos in the January transfer window.
Brede Hangeland on ex Fulham team mate Kostas Mitroglou to Norwegian TV2 "he's too slow, too heavy, too lazy" [for English football]— Tor-Kristian Karlsen (@karlsentk) June 19, 2014
Brede Hangeland's comments that his former team-mate is "too slow, heavy and lazy" for English football suggests Fulham need to cut their losses on the striker sooner rather than later.
His World Cup showing, however, has had the opposite effect to what both player and club would have desired.
Mitroglou is, of course, unlucky to have suffered injury once again - but Fulham fans will wonder whether he was ever truly physically capable enough to play in the Premier League.
The ideal outcome for both parties is undoubtedly a move sooner rather than later - so Fulham fans may hope his injury proves just another minor setback on his road back to recovery.