Juventus touched down in Melbourne on Monday ahead of their two-game ICC campaign, where they will face A-League side Victory and English Premier League outfit Tottenham Hotspur.
Valeri, who returned home to Australia in 2014 after a 12-year stint in Italy, could not contain his excitement ahead of the fixture against Allegri and Juve at the famed MCG.
The 31 year-old was signed on loan by Allegri when the Italian was in charge of SPAL, before being purchased by the 48 year-old when he moved to Grosseto the next season.
Allegri took charge of Juventus in 2014 to replace Antonio Conte, winning the Serie A and Coppa Italia in his first season before going on to repeat the same feat the next campaign.
On facing up against the Allegri-led Serie A champions, Valeri said: "It's going to be fantastic. I played in Italy a long time and I looked up to a lot of the players.
"I was lucky enough to be coached by Allegri for about three years back when I was first starting out in the Serie C and Serie B.
"He is fantastic with the players. He was great getting everyone to play for him and getting the group united.
"He's just grown since then and done some amazing things for Juventus, for Milan, and for the sport."
Juventus are without a host of star names after EURO 2016 in France, with the likes of Paul Pogba, Gianluigi Buffon, Leonardo Bonucci, Giorgio Chiellini, Mario Mandzukic and Patrice Evra absent for the trip to Australia.
However, Valeri believes Juve will still be a difficult task, with Paulo Dybala and Miralem Pjanic among others set to compete against the three-time Australian champions.
"I've heard people saying 'It's not their best team', but it's still an amazing team and they are going to be a tough test for us," Valeri said.
"They're missing their European stars, who deserve a break, but they're still a fantastic team. It's going to be a tough battle.
"They're also going to be playing for something, playing to stay at Juventus, so it will be tough."