Unai Emery said Mesut Ozil did not deserve his place even in a squad packed with youngsters after Arsenal beat Standard Liege in the Europa League.
Ozil, the highest-paid player in the history of the club, was once again left out of the matchday squad as Gabriel Martinelli hit a brace in a 4-0 Group F victory at home on Thursday.
The 18-year-old scored twice in three first-half minutes before laying on Dani Ceballos to score his first goal for the club, Joe Willock having already added the third.
Emery made 10 changes from the side that drew at Manchester United on Monday, with Ozil not making the matchday squad on either occasion.
"I am thinking every time to decide the best players for each match and the best players in the squad to play and to help us," Emery replied when asked about Ozil's omission.
"When I decided he shouldn't be in the squad it's because I think other players deserved it more."
The 30-year-old has had a difficult relationship with Emery since the manager's appointment last year and his absence from the squad will lend weight to speculation that he does not have a long-term future at Arsenal.
On a positive night for the Gunners, Rob Holding, Kieran Tierney and Hector Bellerin, who captained the side, all came through 90 minutes as they continued their comebacks from injury.
Bellerin battled back from a long lay-off with a serious knee injury to skipper the side on his first start since January and was proud to lead out the team.
"There's not a better way to come back," he said.
"I feel very honoured to wear the Arsenal armband and lead the team out. It's been a tough road for me over the past eight months but I feel very lucky to have had my players, family and friends around me."