Manchester City made it into the fourth round of the League Cup by beating West Brom on Wednesday night, but will be concerned about another injury set-back for Ilkay Gundogan.
Leroy Sane scored both of City's goals in a competitive 2-1 win, the second of which a superb individual effort, but his Germany team-mate's return from a nine-month lay-off was cut short.
Gundogan damaged his cruciate ligaments in December and only returned to first-team action at the weekend. He looked sharp on his first start at the Hawthorns on Wednesday, but was hacked down from behind by Baggies midfielder Claudio Yacob.
Pep Guardiola revealed after the game that Gundogan will have tests on Thursday to determine the extent of his latest set-back, although the Catalan stressed it was not as serious as his previous problem.
"I think it's not serious, it's not eight months, but a little injury," he said. "Unfortunately the [foul] is tough. He will be back soon hopefully.
"Tomorrow we will make a test. The doctor told me it's not big issue."
Gundogan had played a role in City's opening goal of the night. His shot came after an unbeliavable string of 54 City passes, meaning Ben Foster's save was the home side's first touch of the match - after two and a half minutes.
Unfortunately for the England goalkeeper, Sane was on hand to fire in a technically superb effort to open the scoring.
Yacob, adding insult to injury, equalised for Tony Pulis' side after Gundogan had been forced off, but Sane netted a superb winner on the counter-attack, haring in on goal and sending a fine strike into the top corner.