Unai Emery heads into Thursday's Europa League quarter-final first leg with Napoli sweating on the fitness of two players whose absence was keenly felt at Goodison Park last week.
Neither Laurent Koscielny (bruised foot) nor Granit Xhaka (groin) were considered fit enough to make the trip to Everton, where, lacking control in midfield and organisation in defence, Arsenal were lucky to escape with a 1-0 defeat to Marco Silva's side.
Speaking after that defeat Emery did not appear entirely optimistic that either player would shake off their injury issues before Napoli visit the Emirates Stadium on Thursday, though Koscielny appears significantly more likely than Xhaka.
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"Maybe Laurent could have come back to play today but yesterday we knew it wasn't possible," Emery told football.london on Sunday. "I want to be positive for Thursday but it depends how he's progressing.
"Xhaka is the same. They are doubts for Thursday.
"We have players and we know we can produce the performance with all the players.
"We've won matches with other players, other systems, and we need to be efficient in each moment. We need to be consistent like we are a lot of the time, but sometimes we can lose."
Xhaka had trained on his own on Saturday whilst Koscielny has not trained since before the win over Newcastle on April 1, where he travelled with the matchday squad but did not feature.
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Whilst those are Emery's two most significant selection doubts it remains to be seen whether Aaron Ramsey will now be deemed fit enough to play from the off having overcome cramp in his groin to make the bench on Sunday, playing 45 minutes in pursuit of victory.
Emery's midfield options will, however, be strengthened by the return of Lucas Torreira. The Uruguayan, banned for three Premier League games after a red card against Tottenham, has played just 92 minutes since being given his marching orders against Spurs.
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Torreira and Guendouzi are likely to be vying for a starting role alongside Ramsey in the first leg. In defence Sokratis Papastathopoulos is almost certain to start - he is banned for the next two Premier League games after picking up his 10th yellow card of the season in the competition.
Another dilemma Emery faces is whether to reunite Pierre-Emerick Aubameyang and Alexandre Lacazette after two matches in which he has deployed a 3-4-2-1. If he does Mesut Ozil is expected to keep his place in the side despite an ineffectual display against Everton which saw him replaced by Alex Iwobi.
Probable Arsenal XI: Cech; Mustafi, Sokratis, Monreal; Maitland-Niles, Ramsey, Torreira, Kolasinac; Ozil; Aubameyang, Lacazette
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