Thirty years after the former Juventus player gave the world l'urlo di Tardelli (the Tardelli scream) he could help to break Italian hearts at Euro 2012 as he swaps blue for green.
Tardelli, assistant to Ireland manager and fellow Italian Giovanni Trapattoni, will bark instructions from the technical area when they play Italy on Monday in their farewell match at the tournament, having lost to Croatia and Spain.
Italy must win to have any chance of qualifying but they will not find any sympathy from Tardelli, at least until after the game in Poznan is over.
"I was once the coach of the Italy Under-21s but I'm a professional coach and my duty is to do everything for Ireland to win the game," he told reporters as Ireland prepared for the match at their training base near Gdansk.
"This is the first time I've played against Italy as a coach. If Ireland win, I will celebrate, why not? I'm a coach of the Ireland team. But I will be sad too for Italy."
Tardelli rejected any suggestion that Ireland's players will not be fully motivated for the match, saying the fact that they are already out could make them dangerous.
"They certainly won't be [carefree]," he said. "Relaxed in their minds maybe. But we want to achieve three points or one point for morale and it's a very important game for us moving forward to the next qualification.
"Italy have more pressure than us because they need to win to achieve and go through but for us it's possible to play a little more relaxed. Possibly that might help us."
Ireland's Damien Duff is expected to earn his 100th cap on Monday and Tardelli hinted that the winger may even wear the captain's armband.
Usual skipper Robbie Keane said he would be happy to hand it over to mark Duff's century.
"It's the manager's decision but it would not be an issue for me," Keane said. "But knowing Duffer he wouldn't want the attention!"
