Raheem Sterling has not been selected in Chelsea's squad to face Newcastle.
The England star was named in Gareth Southgate's World Cup squad on Thursday but has not been included in Graham Potter's plans at St James' Park.
Although there are no reports of an injury, the winger is believed to have picked up an illness ahead of the major tournament next week.
According to beIN Sports, the illness should not affect Sterling's participation at the World Cup.