Ozil made his first appearance of the campaign on Sunday when he started the 2-2 draw at Watford, but was replaced by Reiss Nelson 19 minutes from time.
The 30-year-old trained as normal with the rest of his team-mates at London Colney on Wednesday morning, but was not part of the 19-man squad which flew out to Germany in the afternoon.
And speaking at his pre-match press conference ahead of Thursday night’s Group F opener, Unai Emery revealed that the playmaker had been left behind purely to rest.
“We are playing now a lot of matches and I want to use different players and also can have some rotation in the first 11 and in the 19 players in the squad,” said Arsenal’s head coach. “Sokratis and Mesut they rest this match.”
“I prefer after Sunday’s match [for him] to rest and train and to be ready for Sunday [against Aston Villa].”
Ozil’s start to the campiagn has been disrupted massively by the security scare he suffered towards the end of pre-seaosn when he and Sead Kolasinac were targeted by armed attackers outside the latter’s house in London.
Both escaped unhurt, but further incidents led to both players missing the trip to Newcastle for the opening game of the season.
Ozil then suffered from an illness, delaying his return further, and has only now started to be eased back into the squad by Emery.
Given his lack of game time, the 30-year-old was expected to feature against Frankfurt on Thursday night - in what would have been his first appearance back in Germany since he retired from international football.
The last time he was involved in a match in his homeland, in June 2018, he was subject to boos from German fans during a friendly with Saudi Arabia, having previously been pictured with Turkish president Recep Erdogan.
So there was a thought that his absence from the Arsenal squad to face Frankfurt was connected with the tie being in Germany, but Emery insists he has been left out with Sunday’s Premier League game against Aston Villa in mind.
“We are going to play another match on Sunday,” said the Spaniard, when pushed further on why he had left the club’s highest earner in London.
“My decision is because he played [at Watford] and also I’m thinking about Thursday, with the focus on the first 11, and after that I decided who are the players who can be the best for Thursday. The players [who are] not is Sokratis and Mesut.”
Emery added: “The first match he [Ozil] played on Sunday he played good physically, also giving us his capacity and skills.
“His first minutes for us were good and now he is ready to help us, not on Thursday, but Sunday. On Thursday we are thinking to do some rotation.”