Not at all cech suffered worse type of injury and he capable of continuing after that it's depends on doctor advice it'll maybe require Jeminez wear something in his head like cech not suitable for outfield player.Surley that's Jiminez's career done? Ryan Mason suffered a similar injury if I remember correctly.
As for Luiz, not taking him off was a disgrace decision by Arteta.
Not fair to blame Luiz or mikel not taking him off if you blame someone blame the medical team.