Martinelli was only signed by Arsenal last season, and made 25 appearances in all competitions, and was a regular goal threat for the Gunners, especially in the cup competitions.
It was a Premier League goal, though, that caught Ferdinand's eye. Martinelli ran almost the length of the field to score an equaliser for Arsenal against Chelsea at Stamford Bridge last season.
Ferdinand pointed to that goal, when he was asked to compare Martinelli to the rising Manchester United star Mason Greenwood, on his Instagram page, reported The Mirror.
."To be 18-years-old, doing what he's doing; the goal against Chelsea alone, he runs from the edge of his box - a set-piece against his team - he takes it to the other end," Ferdinand said.
"Normally, your legs are gone by then, you've got no energy and no juice in your legs, but he has the composure to slot it.
"Great player, but the awareness of the way he plays, the way he moves on the pitch, the intelligence to receive the ball, the positions he takes up."
Ferdinand says young Arsenal stars complement each other
Ferdinand also said Martinelli and Bukayo Saka complement each other well, with their movement.
"Martinelli comes inside at the right time to allow Saka to have space on the outside and ask the opposing full-backs the questions; 'Are you gonna come inside with me, or are you gonna stay with Saka?'
"It's mad. He's a mature player for such a young kid."
Martinelli has not played a game this season, as he suffered an serious knee injury just before the Premier League restarted after lockdown, in June.
Arsenal have not made a particularly impressive start to their Premier League campaign, having lost four of their first eight matches.
They have also struggled to find goals, with their star man Pierre-Emerick Aubameyang cutting an increasingly isolated figure on the left wing.
New signing Willian has bene inconsistent, while last season's big-money acquisition Nicholas Pepe has struggled to find a regular spot in the Premier League matchday squad.
Arsenal are still a while away from having Martinelli in the squad, though, with Mikel Arteta sure to be excited to have another attacking threat in his squad.
Check our Tokyo Olympics Coverage here!