Santana was the Rangers player of the year during the 2019 season in a utility role, and went into 2020 as the team's starting center fielder. But he played only 15 games this year and was on the injured list twice before surgery on his right elbow in September 9. He isn't expected to be ready for the start of next season.
General manager Jon Daniel said the team wanted more time to evaluate Santana as he continues his rehab.
"He's been a pro for the two years he's been with us and the door remains open depending on a variety of factors," Daniels said.
Santana went to spring training in 2019 as a non-roster player before hitting .283 with 28 homers and 81 RBI, with at least five starts at every infield and outfield position. He hit .145 with a homer and seven RBI this year.
Herget (1-0, 3.20 ERA) pitched in relief in 19 of his 20 games. Heineman hit .154 with a homer and seven RBI in 24 games.