The 18-year-old attacker scored his second goal of the league campaign, and ninth in all competitions, to give the Gunners the lead initially against Sheffield United.
It was Martinelli’s first 90-minute run-out since before Christmas, having struggled with a hamstring injury recently, and Arteta praised his industry and mentality.
“He’s an 18-year-old kid with all the enthusiasm but as well, he’s so brave to make decisions, to threaten the opponent every time,” said Arsenal’s new manager.
“He’s all the time in the middle of the goal, waiting for an opportunity to come.
“The fact he hasn’t played 90 minutes for a while – since his injury – but is still in the way he went about every single action is impressive.”
Martinelli also drew praise from Arsenal strikers past and present after the game.
Gabi’s gonna be a superstar 🙏🏽 Not because of the Goal because of the attitude Energy and mindset ☝🏽— Aubameyang P-E (@Aubameyang7)January 18, 2020
Pierre-Emerick Aubameyang took to Twitter to laud the Brazilian’s approach to the game, while Ian Wright referenced his movement, sharpness and ability in the box.
Martinelli’s return to fitness and goal threat, whether from the flanks or the centre of attack, is a welcome bonus for Arteta and Arsenal.
Aubameyang has begun a three-game suspension, Alexandre Lacazette hasn’t scored in the league since the start of December and big-money signing Nicolas Pepe only has three league goals all season.
Arteta must now decide whether or not to retain his young forward in the side for difficult away matches, as Arsenal travel to Chelsea and Burnley in the league either side of an FA Cup trek to Bournemouth.
Fans have welcomed his appointment and the start to life under the novice manager, but with just three wins in the last 19 games across competitions, stretching back to under Unai Emery, it has largely been a season to forget, with Martinelli a rare bright spot.