Arsene Wenger has indicated he may continue to rest Petr Cech in the Champions League as he wants to give David Ospina first-team opportunities.
Arsenal face Olympiakos at the Emirates Stadium on Tuesday and Wenger has acknowledged it is a must-win game after their 2-1 loss at Dinamo Zagreb, but he said he had "not decided yet" which goalkeeper would face the Greek side.
Ospina made his first appearance of the season in the Dinamo game but, while there were questions about the decision to rest Cech after the shock defeat, Wenger said he retained full confidence in the Colombia international.
"I need to give Ospina games and I think he is a top-level goalkeeper but that doesn't mean that he will play [against Olympiakos]," Wenger said. "It will go game by game and there can be a different decision. I am fortunate to have two keepers of this quality."
Wenger, who had used the cup competitions to give Wojciech Szczesny game time last season, said after the Dinamo match that he had been seeking to give Cech "some rest mentally" after his return to regular first-team action following his limited involvement at Chelsea last season.
The Gunners had also made six outfield changes in Zagreb but, despite that result, Wenger suggested he could bring in some fresh faces for the visit of Olympiakos after having had games against Tottenham and Leicester in the last week.
"It's more the games we played before which could have an influence on selection," he said. "Some players have played two tough games, at Tottenham and Leicester, where it was a high level physically.
"The 20 fit players I have available can play in every game. I can close my eyes, just take a position, and I am confident I can play a very strong team."
Francis Coquelin is in contention to return from injury while Gabriel is available after a domestic suspension, but Olivier Giroud misses out after being sent off at Dinamo.