The Italian Football Federation (FIGC) gave the all-clear for the Aston Villa player to be called up on Friday for the crucial Group C qualifying games at home to North Macedonia on November 17th and away to Ukraine three days later.
Spalletti told a press conference on Monday: "He (Zaniolo) had nothing to do with that situation (betting on football). There is nothing.
"Before calling Zaniolo I spoke to the President (Gabriele Gravina) and the federation and there was nothing against this."
Italy can book a place at next year's Euros if they beat visiting North Macedonia and avoid defeat away to Ukraine.
Zaniolo was allowed to leave the squad last month before the qualifiers versus Malta and England, along with fellow midfielder Sandro Tonali (23), after the two players were told of their involvement in an investigation by Turin prosecutors.
Last month Zaniolo's Premier League club issued a statement saying: "Aston Villa can confirm Nicolo Zaniolo is assisting the Italian Football Federation (FIGC) and the relevant authorities' investigation into alleged illegal betting activity."
Newcastle United's Tonali has since been banned for 10 months, while Juventus midfielder Nicolo Fagioli (22) accepted a seven-month ban for breaching rules on betting on matches.
Fagioli has made one appearance for Italy but was not in the squad for the previous round of international games.
LOCATELLI INJURED
Spalletti added that he had sent Manuel Locatelli (25) home after the midfielder was injured in training, while Tottenham Hotspur left back Destiny Udogie (20) was left out through injury.
"He (Udogie) is injured, otherwise I would have called him. He made some errors in that game (against Chelsea on November 6th) but he's proved to be a player with strength."
Udogie, who is still struggling with a muscle injury he picked up last month, returned to the Spurs side for their 4-1 loss to Chelsea but was sent off for two bookings as the hosts finished the Premier League game with nine men.
He was suspended for Tottenham's 2-1 defeat at Wolverhampton Wanderers on Saturday.
England, who have already punched their ticket to the finals in Germany, lead the table on 16 points from six games followed by Ukraine, who have played seven, with 13 and Italy on 10.
"If we win the first game, it gives an advantage for the second match," Spalletti added on Monday. "So we must focus on the upcoming fixture (against North Macedonia).
"I don't make my assessments thinking about two games. Of course, we'll make changes, but we take one step at a time."
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