The two players will form the midfield combination against France in Paris on Saturday night.
Tompkins made his first four Test appearances in the Six Nations at the start of the year when Davies was out injured while he recovered from knee surgery.
“I can’t believe it. I have grown up watching Jon which sounds weird now,” said Tompkins.
“It has been brilliant coming into training with him and getting to know him as much as you can.
“He is a lovely bloke firstly, a really nice guy which you hope for. I am excited for the game to see what we can do. It’s nice to have that security on the outside at 13 so hopefully it will be good.”
Davies, 32, made his Wales debut in 2009 when Tompkins was 14.
He has since gone on to become a Wales and British & Irish Lions superstar.
Tompkins, on loan at the Dragons from Saracens this season, and Davies form a hugely exciting centre pairing.
Tompkins will wear the No 12 jersey with Davies at 13.
Tompkins has started three of his four Wales tests at outside centre, but will begin further in when the action gets going in Paris on Saturday night.
Both teams have named strong sides for what looks set to be an entertaining game.
“I am looking forward to playing 12,” said Tompkins.
“There are slight differences and I am looking forward to getting my hands on the ball at the set-piece and things like that.
“Defensively it’s different and brings its own challenges and that’s going to be fun.
“I have played quite a bit there for Saracens back in the day and that’s no problem, but it will be a bit different in the Six Nations.”
