The transactions put Cincinnati’s 40-man roster at 34 players.
Garcia, 24, appeared in four games for the Rays in 2020 and posted a 10.80 ERA over 3 1/3 innings. In 2019 with the Phillies over two stints, he was 2-0 with a 5.77 ERA and 1.64 WHIP in 37 appearances. At Triple-A that season, he had a 2.48 ERA and eight saves in 25 games.
Tampa Bay acquired Garcia from the Phillies in an Aug. 18 trade, but non-tendered him on Dec. 2.
The Reds have been trying to fortify their bullpen with inexpensive options after Archie Bradley was non-tendered and closer Raisel Iglesias was traded to the Angels.
Grullón, 24, has a trace of Major League experience with a total of five games with Boston and Philadelphia over the past two seasons. The Red Sox claimed him from Philadelphia on Sept. 3, and he spent most of the month at their alternate training site but did get a start in one of the games during a Sept. 8 doubleheader.
Over seven Minor League seasons, Grullón is a .253/.305/.405 hitter with 70 home runs in 606 games -- including 108 at Triple-A. He hit a career-high 21 homers in both 2018 and ’19.
Grullón has caught 86 games at the Triple-A level and has thrown out 183 of 628 (29.1 percent) attempted basestealers during his Minor League career.
The Reds already have Tucker Barnhart, prospect Tyler Stephenson and utility player Kyle Farmer as their catchers. But Grullón will provide more depth to work with pitchers and could be an option if there’s a need in the big leagues during 2021.