Chelsea will be nervously awaiting the results of scans on Ben Chilwell's back after the left-back limped off during the first half of England's 2-0 loss to Belgium on Sunday.
Chilwell fell awkwardly shortly after the half-hour mark and was clearly in pain, and despite several minutes of treatment from physios, it was decided that he should not continue the match.
Speaking after the defeat in Leuven, England boss Gareth Southgate said (as quoted by the Metro): "He [Chilwell] had some sort of issue with his back that he was complaining about and he didn’t feel he could carry on. Outside of that I can’t give you any detail at the moment."
There's yet to be any official word on Chilwell's injury, but Chelsea will be praying that all the checks reveal no serious damage as the left-back has been one of the Blues' top performers this season.
He was carrying an injury when he first arrived from Leicester City during the summer, but after finally making his debut, the 23-year-old has managed two goals and three assists in all competitions for the Blues.
Should Chilwell be unable to make it back in time for Saturday's meeting with Newcastle United at St James' Park, Frank Lampard could turn to either Emerson or right-back Cesar Azpilicueta to fill in.
Marcos Alonso is also an option, but the Spaniard hasn't been seen since the disasterous 3-3 draw with West Brom, after which Lampard is understood to have been furious with the left-back's attitude as he tried to sit on the coach by himself instead of returning to the stands to watch the game.
Alonso remains heavily linked with a move away from Stamford Bridge, while doubts also remain about Emerson's future, with Inter regularly suggested as potential candidates to sign both players.
One player who has been linked with a move to Chelsea is 17-year-old Barcelona starlet Alejandro Balde. According to Sport, both the Blues and Liverpool have held preliminary talks with the left-back's representatives, although Barcelona are keen to keep hold of a player dubbed 'the next Ansu Fati' - a nickname which stems more from his potential than his play style.
Balde is expected to be promoted to Ronald Koeman's senior side to compete with Jordi Alba for minutes, and the teenager is understood to be happy with the pathway to the first team that has been set out for him at Camp Nou.
It seems as though a move for Balde may already be off the table, meaning Lampard may have to find other alternatives to Emerson and Alonso if the pair are shipped out in January.