Giampiero Ventura says Mario Balotelli has to show consistency before sealing a return to the Italy squad.
The Nice striker, 26, continued his impressive start to the season with a superb late winner against Lorient on Sunday, although he was sent off in stoppage-time after receiving his second yellow card in the space of six minutes.
Balotelli has scored six goals in five appearances across all competitions this season and had been tipped to earn a recall for Italy, who he last played for at the World Cup in 2014.
However, Ventura opted to leave Balotelli out of his final 26-man squad to face Spain and Macedonia in World Cup qualification despite having given him a pre-call.
"His ability as a player is unquestionable, it's the rest," Ventura said at a media conference.
"His pre-selection was a sign that there are no foregone conclusions about players.
"The pre-call came because he is back to playing and scoring - now it takes consistency.
"The important thing is that the players are playing, in Italy or abroad."
Ventura warned Italy over the scale of their challenge in having to face their biggest rivals to win Group G, Spain, at Juventus Stadium on Thursday.
"It's important, but not decisive," he said. "We are facing the best team in the group.
"The last game they lost in World Cup qualifying was 23 years ago. They are a team which has changed in their approach and how they do things on the pitch.
"It's a different Spain to the past. How they played at Euro 2016 doesn't tell us much.
"They've changed direction and revitalised the team. I can really appreciate [Spain coach] Lopetegui, he's given them ideas and enthusiasm.
"It's inevitable that there will be rotation for the Spain and Macedonia games. They're two fixtures very close together."