The 67-year-old says that the Germany international's all-round display is similar to that of Barcelona's Sergio Busquets.
"Bastian reflects on football on a day-to-day basis," Heynckes told Bayern's official website.
"He thinks about attack and defence at the same time, and is a key reason that we concede so few goals.
"That's one fabulous player, and in my view Bastian shares with Busquets the status of the world's best midfielder."
Bayern are currently 17 points clear at the top of the Bundesliga.