Mikel Arteta and Mathieu Flamini out of Arsenal's Champions League clash with Olympiakos

Midfield pair Mikel Arteta and Mathieu Flamini have been ruled out of Arsenal's Champions League clash with Olympiakos on Tuesday.

Arteta picked up a knock in the 5-2 victory at Leicester on Saturday while Flamini also suffered a hamstring problem in the same game and was substituted after 21 minutes.

Francis Coquelin is back in training, however, and in contention to feature in the Group F clash, but manager Arsene Wenger says he will have to assess all his players' fitness after two games in four days last week.

Wenger said: "They are not big injuries to Mikel and Mathieu - it's a question of days.

"It's the games before that could influence my selection. Some players played two tough games, physically, against Tottenham and Leicester.

"We'll have to analyse that on Monday and make my decisions. I believe that the 20 fit players I have available will make a strong team."

Arsenal lost their opening Group F game away to Dinamo Zagreb, where striker Olivier Giroud was sent off, and with a double-header next against Bayern Munich, Wenger concedes Tuesday's match now leaves no margin for further error.

He said: "You have to win your home games if you want to qualify from the group stage, it is simple as that. We cannot afford to drop points now against anyone at home.

"Olympiakos dominates their league, they are a team with a big advantage - they dominate their league easily, so they can prepare for these kinds of games.

"They are well organised and have some players who know the Premier League, like [Esteban] Cambiasso and [Pajtim] Kasami who both played in England."

Arsenal are still without midfielder Jack Wilshere, who has had an operation on a hairline fracture in his left fibula, while forward Danny Welbeck and Czech midfielder Tomas Rosicky are also both still sidelined with knee injuries.

The Gunners host Premier League leaders Manchester United on Sunday, but that will not impact on Wenger's team selection, although goalkeeper David Ospina could again be preferred to Petr Cech.

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