On April 19, 2019, the Arizona Diamondbacks acquired Swihart, along with international signing bonus pool money, from Boston in exchange for outfielder Marcus Wilson. Swihart was designated for assignment on August 12, 2019. He elected free agency on October 1, 2019.
On December 16, 2019, Swihart signed a minor league contract with the Texas Rangers. On August 25, 2020, Swihart was released by the Rangers organization.
Swihart's older brother, Jace, serves in the United States Army. He has a younger sister, Kacie. Swihart's parents, Carla and Arlan, adopted Romel Jordan, a family friend who came to live with them during high school. Jordan played running back for the University of New Mexico. Jordan died at age 23 in 2019.