Petkovic, who has also managed Turkish side Samsunspor, said Serie A had made him a better coach.
"The coaches there really study the opposition two or three times in the course of the week, to try to get the better of their opponents," he said.
Switzerland captain Stephan Lichtsteiner, now with Juventus after a stint at Lazio, said playing with the Italian champions has given him the chance to train "with some of the best players in the world," and has helped him "improve a lot as an individual."
Other Swiss players can draw on their experience of Italian football. Watford midfielder Valon Behrami has played with Genoa, Lazio, Fiorentina and Napoli, while Blerim Dzemaili, currently on loan at Genoa, has played for Parma and Napoli.
Hamburg defender Johan Djourou, who forms a solid center back pairing with Fabian Schaer at Euro 2016, believes that experience of other leagues has been a key ingredient in Switzerland's success.
"Most of all because the competition is tougher, you need to fight for your spot, and because you are taking on high-caliber players," said Djourou, who left for Arsenal when he was just 16. "In Germany, a defender has to deal with (Pierre-Emerick) Aubameyang or (Robert) Lewandowski."
Switzerland's leading player, Xherdan Shaqiri, is now with Stoke in the Premier League after stints at Bayern Munich and Inter Milan, while upcoming midfielder Granit Xhaka has been signed by Arsenal.
"We are lucky to be split with three big countries (Italy, Germany, France) with different football brands, and we are able to analyze all of that," Petkovic said. "And if we can then add that into your own side, it can be advantageous."
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Associated Press writer Joseph Wilson in Saint-Etienne contributed to this report.