The Brazil Under-21 international signed for the north London club 18 months ago, on the recommendation of former head scout Francis Cagigao.
Martinelli has scored 10 goals in 26 first-team appearances but only played nine games under Arteta before suffering a serious knee injury in training that has kept him out since March.
The teenage forward’s eye for goal and relentless pressing could be important to his under-pressure manager, particularly given how shot-shy Arsenal have been in front of goal this season.
Arteta, however, is worried about placing too much pressure on Martinelli and is keen to temper expectations as the youngster finds his feet at the Emirates once more.
Speaking ahead of the Europa League clash with Rapid Vienna, he said: "“Gabi is another one that even in a moment of adversity, you see him training and everything he brings to the team, his energy, his passion, his motivation, is translating positive emotions to everybody.
“He tries and goes and goes again and wants to score a goal. He is ruthless in training in every single action and the more players and staff you have that add that, at the end that gets translated to what happens on the football pitch and over time you will be stable.
“Gabi’s pressing brings something different to the team and we need players like him. Time is the key word in this industry, and nobody is going to give you time!
"The moment the ball doesn’t go in the net and you lose a football match, you’re going to question all the rest, so with Gabi it’s the same.
“Now he needs time. He’s done it for a period of time and in certain moments throughout a game, but consistently for three years, two or one? He’s never done it. I’m sorry, he’s never done it, so we cannot put that pressure on him.
“It’s like with Bukayo and other young players that we have, they’ve never done it in their career, so why do you expect him to do it today? And in which
environment? In which context? Patience, but he’s a positive guy to have back on the team because he’s such a character.”