Arsenal travel to Valencia tonight (Thursday) for the second-leg of their Europa League semi-final, knowing a place in the final in Baku is just 90 minutes of football away – if they can defend their 3-1 first-leg lead.

In the first-leg at the Emirates last week, Mouctar Diakhaby gave the Spanish side an early lead when he headed home an important away goal just 11 minutes in.

The Gunners fought back though, with Alexandre Lacazette scoring twice and Pierre-Emerick Aubameyang volleying a late third to send Unai Emery's men to the Mestalla with a convincing aggregate lead.

The second-leg in Spain has also taken on even more importance, with winning the Europa League now the only way Arsenal can get back into the UEFA Champions League after a 1-1 draw with Brighton on Sunday all but ended their chances of finishing in the top four in the Premier League.

After the first-leg win, Emery - who is returning to the club he managed between 2008 and 2012 - insisted that the tie is still '50/50', despite the Gunners' 3-1 advantage.

"Our idea and my thoughts now is that it continues to be very difficult in the second leg away," he said.

"It's 50/50 and it's a good result at home in the first leg, but the second leg is going to be very difficult and maybe different. I consider that for two teams it's 50/50.

"We are going to prepare for the match thinking that this round is 50/50 for both.

"We need also to play there thinking to win, thinking to score, thinking to defend well and thinking also to take our moments in attack.

"We can control with the ball and possession, but we don't know because they are going to feel strong with their supporters there."

Valencia warmed up for the second-leg at the Mestalla by relegating Huesca, thumping them 6-2 in La Liga including doubles from Rodrigo and Santi Mina.

Former Arsenal man Francis Coquelin will be available tonight after he completed his suspension, although Los Ches will be missing injured midfielder's Geoffrey Kondogbia and Denis Cheryshev - who starred for Russia at last summer's FIFA World Cup.

The Gunners will welcome back Ainsley Maitland-Niles after he sat out the draw with Brighton through suspension, while Petr Cech will take the place of Bernd Leno in goal, as he has done throughout the Europa League campaign.

If Emery's men are to progress to the final, they will have to overcome the club's Mestalle hoodoo, with Arsenal having never won at the ground.