The 31 year old Spaniard missed five months of the 2015/16 campaign with a serious knee injury, but made his first pre-season appearance during the Gunners' 3-1 win over Chivas on Sunday.
"He is our technical security in midfield and we missed him for five or six months last season," he told reporters. "At the moment he is not completely there on the fitness front. That's why I took him off at half-time.
"He's a bit behind the others physically but I think he will be alright, maybe not on August 15th, but at the end of August he should be alright."