Mason Thompson recalls watching big leaguers Nelson Cruz, Josh Hamilton and Lance Berkman play in limited stints at Dell Diamond. Thompson grew up a tall and lanky teenager, likely to be found playing at the Dell Diamond basketball court when he wasn’t pitching for the Round Rock High School baseball team.
Now 28, Thompson is still tall and lanky – standing at 6-foot-6, 241 pounds – but has traded in the “RR” and maroon of the Dragons baseball team for the double R and colors of the Round Rock Express. He’s the first Express player born and raised in Round Rock.
“It’s been cool having a lot of familiar faces at the game so far,” said Thompson, noting he pitched in the Express’ home opener. “There was definitely an extra level of excitement. I felt I had an extra edge out there that night.”
Thompson was drafted out of Round Rock High by San Diego in the third round of the 2016 MLB Draft. He was the youngest player to ever commit to play baseball at the University of Texas in former coach Augie Garrido’s tenure there, but that changed after his third-round selection by the Padres.
He has since appeared in the big leagues over parts of four seasons with the Padres (2021) and Washington Nationals (2021-23, 2025).
In Triple A with El Paso in 2021, he got his first chance to play in front of friends and family at Dell Diamond. For some of his relatives and friends, it was the first time they’d ever seen him pitch.
“That was a real cool experience,” he said, noting he was called up to the Major Leagues shortly after that game.
Thompson had a 2.85 ERA as a varsity reliever as a freshman for the Dragons, committing to UT before the end of that school year. He was already 6-foot-5, though his hair was shorter and he had yet to grow the beard he wears nowadays.
In 2023, he got to play in Houston as a member of the Washington Nationals, with friends and family turning out for that game as well. Among those there was his grandfather, a lifelong St. Louis Cardinals fan and pivotal influence in his baseball career. He was in touch regularly with Thompson during his professional career, often providing him pitching tips during phone calls, before he passed two years ago.
“He’d be very proud. He’d be someone who’d be here probably every game,” Thompson said. “Sad to not have him here but I know he’s here in spirit and he’s always on the back of my mind.”
Thompson missed the entire 2024 season as he recovered from his second Tommy John surgery but returned to play for the Nationals last year. In October, he elected to seek free agency, and in February he landed with the Rangers on a minor league deal.
The move has allowed him to enjoy home-cooked meals with his wife and sleep in his own bed during the baseball season – benefits baseball players don’t always get to enjoy. His mom has also been a regular at home games.
On April 1, he pitched 1.1 innings as a reliever for the Express in the team’s 2026 home opener. He allowed a walk but no hits and no runs.
Catch Mason Thompson and the Express in action at Dell Diamond through the 2026 regular season. Tickets are currently on sale online at RRExpress.com
