Calhoun was drafted by the Los Angeles Dodgers in the fourth round of the 2015 MLB Draft. He made his professional debut with the Ogden Raptors and was later promoted to the Great Lakes Loons and Rancho Cucamonga Quakes. In 73 games between the three levels, he hit.316 with 11 homers and 47 RBI. To start the 2016 season, he was promoted to the Double-A Tulsa Drillers of the Texas League. He was selected as a starter for the mid-season Texas League All-Star game and selected to the U.S. team for the All-Star Futures Game. At the conclusion of the season, he was also named to the post-season all-star team. In 132 games for the Drillers, he hit.254 with 27 homers and 88 RBI. After the season, the Dodgers assigned Calhoun to the Glendale Desert Dogs of the Arizona Fall League. He earned MVP honors in the Fall Stars Game for top prospects playing in the league when he went 3 for 3 with a homer in the game. He was promoted to the Triple-AOklahoma City Dodgers to begin the 2017 season and played well enough to be named the starting second baseman for the Pacific Coast League mid-season all-star team.
Texas Rangers
On July 31, 2017, Calhoun was traded to the Texas Rangers in exchange for Yu Darvish. He was promoted to the major leagues for the first time on September 12, 2017. Calhoun hit.265/.324/.353/.677 with a home run and 4 RBI in 13 games in 2017. In 2018, Calhoun hit.222/.269/.333/.602 with 2 home runs and 11 RBI in 35 major league games. In 108 games with the Triple-A Round Rock Express, he hit.294/.351/.431/.782 with 9 home runs and 47 RBI. In 2019, Calhoun was optioned to the Triple-A Nashville Sounds to open the season. On May 15, he was recalled to replace the injured Elvis Andrus, making his season debut the same day. In the midst of batting.435/.458/.739/1.197, he was placed on the 10-day IL on May 22 with a strained left quad. He was reactivated from the IL on June 17 but was optioned back to Triple-A Nashville on July 16 after hitting.225/.267/.408/.675 in second stint in order to clear a spot for All-Star OF/DH Hunter Pence on the roster. On July 25, he was recalled to replace the injured Joey Gallo, and he would play with the Rangers for the remainder of the season. Calhoun would finish the 2019 season batting.269/.323/.524/.848 with 21 home runs and 48 RBI in 83 games. On March 8, 2020, during a spring training match against the Los Angeles Dodgers, Calhoun was struck by a 95 MPH fastball in the face by Julio Urias. The impact fractured and displaced Calhoun's jaw. He underwent surgery the next day.
