Rice saw action for the Euro qualifying win against the Czech Republic.
"From the first moment he trained with us, we noticed he was a serious guy, a big professional, crazy to learn," said Bilic, who introduced Rice as a substitute against Burnley in May 2017 and then gave him a first start at Southampton the following August.
"He has a bit of everything; very strong in the tackle, good in positioning himself, decent quick and hungry for the second ball.
"We got him mainly as a centre-back in training, then we put him as a holding midfielder because he keeps the position there and can pass the ball.
"He's like the metronome, he keeps the balance of the team, doesn't go up or down or left or right. He stays in position which was unbelievably mature for his age."