The American, who came off the bench in his side’s disappointing defeat at home to Southampton on Boxing Day, picked up the muscle injury while running in training the next day.
Pulisic’s injury is not believed to be too serious at this stage, but he has been left out of the squad that takes on Arsenal as a precaution – especially with the festive games coming thick and fast.
Our 11 to face Arsenal! 👊
— Chelsea FC (@ChelseaFC) December 29, 2019
Manager Frank Lampard makes two changes from the side that lose to Southampton, with Jorginho and Callum Hudson-Odoi dropping out for Mateo Kovacic and Mason Mount.
Aside from Emerson, who starts in place of Marcos Alonso, it is the same team that performed so well away at Tottenham a week ago.
Neither Alonso nor Reece James were deemed fit enough for a place on the bench, so versatile 19-year-old Tariq Lamptey earns a spot in the squad.
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Arsenal, meanwhile, have made two changes of their own, with Matteo Guendouzi and Calum Chambers both coming into the side.
Granit Xhaka, whose agent claimed he has an agreement to leave Arsenal and return to the Bundesliga, has been left out of the squad due to illness.
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