James Maddison limped off injured in his final club game before joining up with England's squad for the World Cup in Qatar.
Thursday's announcement saw him included in Gareth Southgate's squad for the tournament having previously picked up just one cap, three years ago.
But after scoring a superb strike to put Leicester City 1-0 up away at West Ham, Maddison was then forced off through injury in the 25th minute, clutching at his hamstring.
The news will come as a big blow to Southgate, who said Maddison had "earned the right" to be included after registering the second most Premier League goal involvements among England players in 2022 behind Harry Kane.
With the Three Lions' opening group game against Iran just nine days away, Maddison faces a nervy wait to find out the extent of his injury.
If Maddison is ruled out, Southgate could call on Ivan Toney in his place, with the Brentford striker responding to missing out on Southgate's squad by scoring both of his team's goals in a shock 2-1 victory at Manchester City.