Romelu Lukaku has handed Everton manager Ronald Koeman a scare after picking up an injury on international duty with Belgium.
The striker was substituted during his national side's 4-0 victory over Bosnia-Herzegovina on Friday after suffering with a thigh problem, before he sat out their 6-0 win over Gibraltar on Monday.
Koeman will be hoping that the injury is not too serious as his side travel to Premier League leaders Manchester City on Saturday looking to build on their encouraging start to the season.
Everton sweat over fitness of Jagielka, Baines and Lukaku
Lukaku continued his fine form for both club and country on Friday night as he scored his eighth goal of the season in Belgium's victory over Bosnia-Herzegovina. There was no doubt some concerned faces in Merseyside when the 23-year-old was replaced by Crystal Palace's Christian Benteke in the 82nd minute after appearing to suffer a thigh problem.
The striker sat out Belgium's 6-0 win over Gibraltar on Monday night and it will be a significant blow for the Blues if Lukaku was to miss Everton's trip to the Etihad Stadium on Saturday.
Ronald Koeman is already sweating over the fitness of captain Phil Jagielka, who was forced to withdraw from England duty with a thigh injury, while fellow defender Leighton Baines has also been struggling with an injury.
Possible replacements for Lukaku?
Of all the players the Everton manager would not want to be without, Lukaku is probably top of the list. The Belgian has rediscovered his scoring touch after 11 games without a goal for Everton, scoring five goals in six Premier League appearances this season.
If Lukaku is unable to play against Manchester City, then the most obvious solution would be for Koeman to the other recognised strikers within his squad. Enner Valencia has experience of playing as a line-leading forward in the Premier League, but he has made just three appearances for the Blues since joining on loan from West Ham, with his only start the EFL Cup defeat to Norwich City.
Arouna Kone scored seven goals in all competitions last season, including a hat-trick against Sunderland, but he has not started a game all season and was last in the matchday squad for the Norwich game. When Lukaku missed the opening day game against Tottenham Hotspur, Koeman opted to use Gerard Deulofeu in a forward position and the Spaniard could be used in a similar role on Saturday should Lukaku be unable to play.