Two experienced Arsenal players Mesut Ozil and Sokratis Papasthathopoulos were left out of the Europa League squad for the opening match with German Bundesliga side Eintracht Frankfurt.
Ozil and Sokratis were both left out of the 19-man Arsenal squad named by Gunners boss Unai Emery.
The Arsenal manager was quizzed by journalists on the decision at his pre-match press conference before the game on Thursday night.
At his presser on Wednesday, Unai Emery said that the two players were rested for the Eintracht Frankfurt game.
He was further asked to explain how Mesut Ozil needed a rest having played just one game all season.
Mesut Ozil made his first appearance of the new season in the disappointing Premier League meeting at the home of Watford as the Gunners lost a two-goal advantage to play out a 2-2 draw with the Hornets.
On his response to the question on Ozil, Unai Emery said he considered the upcoming Premier League match at home to newly promoted side Aston Villa on Sunday.
The target for Unai Emery and Arsenal is to win the Europa League title this season having come close to winning last season before they were stopped by London rivals Chelsea in the finals.