Former Dragons and Bath forward Faletau has played only 30 times for Cardiff since signing in 2022, but a one-year contract extension was announced at the start of July.
“We all know that he is a quality player and you just feel and sense when he is around that something special is going to happen, either from him or the guy next to him” said Van Zyl, whose side play a friendly at Worcester on Saturday.
“Still in training, every time he steps in, you feel the difference. He brings a lot and gives everybody confidence. He’s a world-class athlete.”
Faletau racked up the games with club and country when with Dragons between 2009 and 2016 but has since been plagued by injuries.
Van Zyl hopes that a summer off and full pre-season will help him thrive at Cardiff, where his game time will be managed thanks to the presence of Alun Lawrence and Taine Basham.
“I think for his body, it’s been good,” said the head coach. “His fitness levels are up there, it’s the contact conditioning that he needs to top up now.
“In different years, he’s had different injuries but he looks in a good place.”