The 34-year-old was substituted on 38 minutes after breaking down with the problem and could miss up to five matches bookended by Premier League and FA Cup showdowns with Manchester City, and games with West Ham, Crystal Palace and Middlesbrough.
On Sunday, Cech told press in his homeland that Arsenal’s players were struggling to replicate their training ground preparations on the pitch and criticised the squad for not hitting their potential.
David Ospina, whose gaff led to West Brom’s second goal on Saturday, looks set to continue in goal. That’s assuming he doesn’t get injured on international duty with Colombia who face Bolivia at home and then travel to Ecuador in six days time.
Emiliano Martinez will likely be on bench.