Whelan told liverpoolfc.tv: "It's taken a while for his first goal to come but it's no surprise really because for me he's playing his best football right now. He's getting around the pitch, breaking things up and then setting things in motion.
"He's an all-round player. Obviously he's not the biggest so he's not great in the air, but if you want a midfielder to get you the ball quickly and set things rolling, then he's perfect. He does his job very well.
"Eric Cantona used to talk about Didier Deschamps being the water carrier and how good teams need one. Mascherano is just that for Liverpool. I used to do a lot of that kind of work in midfield: the clearing up and starting things rolling again. I gave the ball to the likes of Barnes and Beardsley like Mascherano gives it to Gerrard and Torres.
"Hargreaves does the job for Manchester United. He cost about the same but hasn't set the world alight. I think Mascherano was a better buy. He does more, for me."