The Norwich City defender was recalled to the squad by Steve Clarke for the Euro 2020 play-off win against Serbia last November after almost three years in the international wilderness.
The 29-year-old has now made the central defensive position his own after starting Scotland' s last six matches which included impressive performances in the Euros and against Denmark and Moldova.
“He’s been a rock," Carver said.
“And certainly since I’ve been here, he’s been our most consistent player.
“He’s a beast, he’s an animal.
“But you know what, off the park he’s low maintenance. He’s one of the nicest guys.
“He’s up first thing in the morning for breakfast, cheerful, big smile on his face.
“He’s a gentle giant.
“I like how he is off the pitch and I love the way he is on the pitch.
“He gives everything.
“Let’s not forget, he’s approaching 40 caps over 10 years.
“He didn’t get a cap for three years.
“But since he’s come in he’s been amazing. He was a big loss when we lost him against Croatia in that final game of the Euros."
“You can see he’s worked extremely hard to get himself fit.
“He’s had a tough start to the season with Norwich.
“But from a personal point of view, he’s the linchpin for us – that’s for sure.
“I think he’s got a good few years left in him, the way he’s playing at the moment. He’s stepping up to the plate and we’re all delighted with him.”