Walker was forced off in the first-half of England’s 1-0 defeat to Brazil at Wembley.
And there was further bad news when Stones had to come off with injury in the first few minutes of England’s 2-2 draw with Belgium.
The City boss didn’t expand on the length of time either defender will be absent.
“Kyle’s [injury is] more tough than John’s but they will be out- I don’t know for how many games,” said Pep.
On a brighter note, Guardiola added that Ederson is “much better” and added the Manuel Akanji was “okay”.
Kevin De Bruyne could also be available for the visit of the Gunners.
The Belgian - along with England international Jack Grealish - both trained on Thursday and could be in contention for Sunday having both been unavailable for international duty.
