The 30-year-old moved to Bayern for the following campaign but it is Pirlo who Borghi – Vidal's coach at Colo Colo during the early stages of his career – feels is responsible for establishing him as one of the world's top midfielders.
"He is much more mature, he is bigger and has experience," Borghi told La Tercera.
"In my humble opinion, his great change occurred in Italy, playing for Juve next to Pirlo.
"I think Andrea Pirlo was the one who instructed him and taught Vidal how to play football."
Marcelo Bielsa is credited with instilling a philosophy that, following Borghi's depature in 2012, Chile sought to recover with the appointments of Jorge Sampaoli and Juan Antonio Pizzi.
Sampaoli led Chile to Copa America glory in 2015 and Pizzi replicated the feat a year later, but Vidal said last week that Bielsa had nothing to do with their recent success.
However, Borghi feels his fellow Argentine's impact on the national team cannot be overlooked.
He said: "Bielsa did a lot for Chilean footballers. Essentially, he made them understand they could play the same everywhere.
"Now, if you go by results, Vidal is right, he did not win anything with it. But who wins is not always the most important thing."