Man City 2-2 Arsenal: Guardiola may be facing significant issue
We may not know for a few days what the damage of Manchester City's draw with Arsenal is.
As manager Pep Guardiola pointed out, Rodri is not the type of player to leave a game early, so the fact he did suggests the injury he suffered in the opening stages of the game is serious.
It is well-established how important he is to this City team, so if the Spain midfielder is ruled out for any length of time, it is bound to have an impact on their chances of extending their run of four successive Premier League titles.
Mateo Kovacic is an excellent player and the return of Ilkay Gundogan means there are options for the centre of City's midfield.
But Pep knows - like everyone knows - no-one can replace Rodri. He is possibly the single most important player in the City squad.
In a season of off-field issues, Guardiola could be about to be presented with a pretty significant one on it.