"I think he's going to be okay," the Arsenal boss admitted.

"With all respect, last season we were looking [at the bench] and we had five academy players there, that probably never played professional football in the Champions League, so it makes a difference...

It was a largely dominant performance from the Gunners at the Emirates Stadium, producing 2.73 expected goals (xG) from 16 shots to Olympiacos' 0.51 from 10 attempts.

With the tension rising Saka was summoned from the bench, and the England winger had boss Mikel Arteta breathing a sigh of relief when he hit the second two minutes into stoppage time.