Balotelli, who is not in the squad for this month's World Cup qualifiers against Spain and Macedonia, did not play at all for his country in the two seasons in which Antonio Conte was coach.
But he has enjoyed a revival since joining French Ligue 1 side Nice on a free transfer from Liverpool, scoring five goals in three league appearances.
"I've said from the first day that I won't close the national team door to anyone," Ventura told reporters.
"There is no arguing about his technical qualities, it is everything else that is up for discussion.
"He has started playing and scoring again and there is no doubt about his qualities, but he has to continue giving these performances."
Balotelli has scored 19 goals for Italy and made the last of his 47 appearances in the 1-0 defeat by Uruguay at the 2014 World Cup.
Italy host Spain in a World Cup qualifier on Thursday, having beaten Israel away in their opening game.
"It's an important game but not a decisive one," said Ventura.
"They’re a team who have changed in their approach and the way they do things on the pitch.
"This coach (Jules Lopetegui), who I greatly admire, has given them adrenaline, conviction and a made them a completely different team. It’s a different Spain to the past.”
Only the group winners are assured of a place in Russia in 2018, while the best eight runners-up in the nine European groups take part in two-legged playoffs for four more places.
(Writing by Brian Homewood, editing by Ed Osmond)
