Foster rates the defender the club's best performer.
He said: "It’s a close one for me. It would be either Romelu Lukaku or Gareth McAuley.
"But I would give it to Gareth because, as somebody who plays right behind him as a goalkeeper, I know what I’m going to get from ‘G-Mac’ all the time.
“He’s not a moaner or a shouter, he just gets on with it and it’s great to have someone like that in front of you.”