Pep Guardiola will manage Vincent Kompany's latest injury with caution after the Manchester City captain was substituted during their 2-1 Premier League win at Crystal Palace.
Kompany suffered a head injury in an accidental collision with City goalkeeper Claudio Bravo and, although the Belgium international tried to play on, he was replaced before half-time.
The defender is now a doubt for City's crunch Champions League clash at Borussia Monchengladbach on Wednesday after Guardiola indicated he will not rush his skipper's return.
"He had a problem with his head," said Guardiola. "[He got] a kick.
"Now we're going to control him. You have to be careful with head injuries.
"Hopefully it won't be anything serious."
Kompany was a late withdrawal from the Belgium starting XI to face Netherlands during the international break and Saturday's game was his second Premier League start of the season.
City were indebted to a double from the returning Yaya Toure as they recorded a 2-1 win at Selhurst Park.