DALLAS – The butterflies fluttered in Klay Thompson's stomach for days before Thursday night's preseason game, his first NBA appearance not in a Golden State Warriors uniform.

“I don't think I've been this nervous since the first Finals game in 2015,” Thompson said after scoring 10 points in 18 first-half minutes during the Mavs' 107-102 loss to the Utah Jazz. “It felt so good to just go out there and play and get rid of the nerves. It was a new experience and it's a natural feeling when you've been somewhere for so long and you're in a new place in a new environment. To conclude, “When I had the uniform on, it felt great.”

Thompson spent the first 13 seasons of his career with the Warriors and played a key role in four NBA championships as half of the “Splash Brothers” alongside Stephen Curry. But he decided to join Dallas as a free agent this summer.

“I’m just excited to experience a new chapter,” said Thompson, who took a break during the Mavs’ season opener Monday night. “It will be special. I just know it.”

Thursday marked the first time Thompson wore No. 31 in the NBA, as his familiar No. 11 belongs to Kyrie Irving in Dallas. Thompson chose his new number as a tribute to Hall of Fame shooting guard Reggie Miller, a childhood favorite who Thompson will likely pass for fifth place on the all-time 3-point list this season. But Thompson also appreciates its historical significance in Dallas. It was last worn for the Mavs by Jason Terry, the 2009 Sixth Man of the Year who was a key part of Dallas' 2006 Finals team and 2011 championship squad.

Terry, who was on the visiting bench Thursday night as an assistant coach for the Jazz, said he was fine with Thompson wearing his old number.

“The fact that he's wearing the headband as well makes me very happy,” Terry, who wore a headband throughout his playing career, told ESPN. “All I said (to Thompson) is he just owes me a few shots. That's it. Get the number right, that's it. Take a few shots. And he will do it. I think he's going to play with a lot.” Obviously he did some great, historic things with Golden State, and he wants to start a new chapter and further stamp his legacy here with Dallas.

The crowd at American Airlines Center cheered as Thompson was introduced to the Mavs' starting lineup. The home fans had to wait until the second quarter for his first basket as he missed his first three shot attempts and dished up two free throws during his nine-minute stint in the first quarter.

On the first possession of the second quarter, after Thompson said his nerves had calmed during a brief break on the bench, he rolled off an off-ball screen and launched a catch-and-shoot jumper from slightly up the right side of the court bow. He got a bounce as the ball bounced off the rim and touched the glass before going into the basket. It was one of three 3-pointers he made in the quarter.

“There are a lot of positives for him tonight,” Mavs coach Jason Kidd said. “He has some great looks that we all think he's capable of, but he just never rushes things. He never forces anything. He's probably turned down some shots that we would encourage him to take, but we trust him to make the right decision.”

Thompson said he feels some tightness in his back but is ready for Monday night's preseason game at the LA Clippers.

Mavs superstar Luka Doncic, who missed both preseason games because of a bruised left calf, will again miss Monday but could participate in the “dress rehearsal” preseason finale on Oct. 17 against the Milwaukee Bucks, according to Kidd.