PREVIEW By Arsenal correspondent Tony Hughes

Mission Improbable or not, Arsene Wenger will select a team for Wednesday’s showdown against Barcelona that he hopes can inspire one of the greatest turnarounds in Champions League history.

Wenger is unlikely to follow Mauricio Pochettino’s lead and take the controversial option of keeping big guns in reserve to prioritise the Premier League at the weekend.

Despite needing to shut out the world’s most free-scoring team while scoring at least two goals of their own at Barcelona’s fortress, Wenger will be ever optimistic of somehow progressing from this last-16 tie.

First-choice full-backs Hector Bellerin and Nacho Monreal are set to return in place of Calum Chambers and Kieran Gibbs after being given breathers in the last two matches, while Laurent Koscielny is likely to start if he passes a fitness test on a calf injury.

Both Per Mertesacker and Gabriel have looked vulnerable without the Frenchman alongside them, but the Brazilian could get the nod due to his greater mobility.

The big decision could rest on who to spearhead an attack that has faded badly in recent months.

Danny Welbeck did more in the final 15 minutes of the Gunners’ 2-1 defeat to Watford on Sunday than Olivier Giroud had in the previous 75 and could be given the nod to spearhead the attack following his impressive form since his 10 months out with a knee injury.

Theo Walcott put a lean spell behind them to score twice against Hull last week, which could give him the edge over Giroud and Joel Campbell.

Arsenal (possible): Ospina; Bellerin, Gabriel, Koscielny, Monreal; Elneny, Coquelin; Walcott, Ozil, Sanchez; Welbeck.