Reds halfbacks Will Genia and Quade Cooper are wary of Waratahs full-back Israel Foalu ahead of the teams' clash in Sydney on Saturday.
Folau scored a hat-trick of tries in the Waratahs' 43-21 victory over the Western Force on Sunday and Cooper and Genia believe they have an almost impossible task if they want to keep the code-hopper quiet this weekend.
"He's worked very hard at his game in terms of positional play and understanding the role of a fullback and it showed out during the Wallabies' Spring Tour (last November)," Cooper told the West Australian.
"He's the type of guy who wants to be the best at what he does and he has the drive to do that.
"When I got to know Izzy I got to see how he operates and everything he does is very professional - it's all based around his performance and how to be a better player, and I learned a lot off him."
Genia echoed Cooper's sentiments and believes Folau's professionalism would help him to improve during his second season.
"I honestly didn't think he was going to be as good as he is," Genia said.
"It's incredible how quickly he picked up the game.
"I think he can get better. He's got that remarkable thirst to want to be better, and there's areas he wants to improve."