Gunners manager Arsene Wenger is left to rue a damaging round of midweek friendlies as the French defender is forced off against Germany and the England star is reportedly stricken
The France centre-back was forced to withdraw during his country's 2-1 defeat to Germany as a calf injury ended his eighth appearance for les Bleus.
After captain Thomas Vermaelen sat out Arsenal's last domestic outing, a 1-0 victory over Stoke City, Wenger may yet have to turn to Sebastien Squillaci to plug the gap in his back line.
Midfielder Ramsey had to pull out of the Wales squad on the day of their fixture against Austria due to a calf strain in a game that Chris Coleman's men went on to win 2-1 thanks in large part to Gareth Bale.
Walcott played 76 minutes of England's 2-1 triumph over Brazil at Wembley before being replaced by Aaron Lennon but there were reports that the in-form forward was seen hobbling in the mixed zone after the match.
The likes of Santi Cazorla traveling all the way to Doha in Qatar for Spain's win over Uruguay could also add up to give the Frenchman a headache when his side travel to Wearside on Saturday.