Boselli shone in their Capital One Cup victory over Nottingham Forest last week.
"We are very, very exited about Mauro," Martinez said. "He had a difficult period in the previous two seasons but mentally he's come back really refreshed and I think his experience in Argentina has helped him to be desperate to come here and be successful.
"A typical goal-scorer needs to get an advantage into a defender and probably what Mauro does really well in that box is he comes alive.
"He sees that space and, obviously, you need good service. But you always need goalscorers and a goalscorer is precious. I think he's happier now than he's ever been in the previous pre-seasons.
"I see him now with a bit of light in his eyes.
"He's desperate to work hard for the team and have an opportunity in the league."