Manchester City midfielder Rodri was substituted after just 40 minutes during the Champions League clash against Atalanta with a suspected hamstring injury.
City's record signing again started in defence alongside Fernandinho and pulled up with the problem after clearing the ball for a corner.
Rodri instantly grabbed the back of his leg and it was quickly communicated to the bench that he would be unable to continue.
Fortunately for Pep Guardiola, John Stones was on the bench, but the City boss was furious with how long it took the England international to get his training gear off.
Rodri's injury adds to City's injury woes this season with Nicolas Otamendi not present in the last two match day squads with a back problem.
Fernandinho would be the natural replacement in midfield but the Brazilian has been forced to step into the back four with Stones and Aymeric Laporte spending time on the sidelines.
The extent of the problem is currently unknown but City will hope it isn't a long-term problem with crucial Premier League fixtures just around the corner.
City face Liverpool at Anfield on November 11 before welcoming Chelsea to Stamford Bridge on November 23.
