In an update released 24 hours before that first clash at the Amex Stadium, the Gunners announced that Gabriel had now returned a positive test, but expressed hope that he could return after those next pair of games.
After West Brom, Arsenal have an FA Cup and league double-header against Newcastle sandwiched between an all-London top-flight meeting with Crystal Palace on January 14.
“Gabriel has tested positive for COVID-19 and is isolating according to UK Government and Premier League protocols,” Arsenal said via their official website.
“We will continue to monitor and support Gabriel, and we are hoping he will be available again after our next two matches.”
Mikel Arteta hopes Chelsea win will be a turning point for Arsenal
There was better news from Arsenal on the fitness of Thomas Partey, who has now begun training outside as he continues to work his way back from a second thigh injury.
Meanwhile, Brazilian duo David Luiz and Willian are due to rejoin full training on New Year’s Eve after missing the win over Chelsea through illness.
The pair had both recently tested negative for Covid-19.