Manchester United boss Ole Gunnar Solskjaer admits Marcus Rashford may miss today's FA Cup tie with Leicester City.
If he does not make the sixth-round tie then Solskjaer fears he will have to withdraw him from World Cup qualifiers against San Marino, Albania and Poland.
Rashford was replaced by goal-hero Paul Pogba in Thursday's Europa League 1-0 win over AC Milan.
The 23-year-old has had a series of injuries and was frequently troubled by a back ailment.
Solskjaer is unsure how serious Rashford's current problems are.
He said: “I don't know to be honest. He struggled a little bit in Milan so he's doubtful for Sunday but we hope he will be OK.
“Of course if he can't play for us then it is more difficult to go and travel with England because then it is more serious than just a day or two."
