With the world's best football tournament just 50 days away, we take a look at the players who have a race against time to regain their fitness.
Alex Oxlade-Chamberlain was taken off on a stretcher in the first half of Liverpool's Champions League semi-final victory over Roma on Wednesday.
It was confirmed on Thursday that the midfielder would unfortunately miss out for England this summer, though the club was unwilling to put a time-frame on the issue.
It is the time of year where any injury draws questions about availability at the World Cup - so we have taken a look at which players face an anxious wait to see if they can recover in time.
11 injury doubts for Russia
1. Neymar (Brazil, above) - Broken foot: Final examination due in mid-May
Brazil are the 9/2 favourites to win the World Cup
2. Sergio Aguero (Argentina) - Knee surgery: End of season, according to Pep Guardiola
Aguero is 25/1 to win the World Cup Golden Boot
3. Mohamed Elneny (Egypt, below) - Ankle ligament damage: May return in time for Arsenal's final game of the season, Sky Sports News understands.
4. Alex Oxlade-Chamberlain (England) - Knee ligament: Ruled out for the summer, at least
5. Adam Lallana (England, below) - Hamstring: End of season, rehabilitation in South Africa with World Cup in mind
6. John Stones (England) - Abductor: Guardiola hopeful he will recover in time
7. Gylfi Sigurdsson (Iceland) - Knee: Hopeful to return in May
8. Manuel Neuer (Germany) - Metatarsal fracture: Returned to first-team training, match action unknown
9. Michy Batshuayi (Belgium, above) - Ankle: World Cup fitness in doubt, player recently said he is making good progress already
10. Diego Costa (Spain, below) - Hamstring: After initial doubts, he is part of Atletico Madrid's squad travelling to Arsenal
11. Kingsley Coman (France) - Ankle: Pictured on crutches in April after picking up problem in March, hopeful of returning in time
Posted at1205 BST 25/04/18.