Both Harrell and Tolleson were on the 60-day disabled list, Harrell because of a right groin strain and Tolleson due to a lower back strain.
Tolleson began the 2016 season as the Rangers' closer but was sent to Triple-A Round Rock after the team acquired Harrell from the Atlanta Braves on July 27. In 37 relief appearances this past season, Tolleson was 2-2 with a 7.68 ERA. He was 11-for-15 in save opportunities and lost his job as the closer after blowing consecutive saves in May. Sam Dyson took over the closer's role.
Harrell was 1-0 in four starts for the Rangers, and 3-2 in nine total starts. He posted 4.21 ERA, 1.51 WHIP and struck out 36 batters in 47 total innings this season. As a Ranger, Harrell had 15 punchouts in 17 2/3 innings.
Harrell and Tolleson both have the option to decline a minor league assignment from the Rangers and can be claimed by another team.