[citation needed] The Detroit Tigers selected Greiner in the third round of the 2014 Major League Baseball draft.

However, Greiner improved greatly in 2016, where he split time among Lakeland, the Erie SeaWolves, and the Toledo Mud Hens, posting a combined .293 batting average with seven home runs and 42 RBIs between the three clubs.

[5] After the season, the Tigers assigned Greiner to the Salt River Rafters of the Arizona Fall League.

In 2017, Greiner played for both Erie and Toledo, batting a combined .237 with 14 home runs and 44 RBIs in 103 total games between the two teams.

[15] Greiner made the Tigers Opening Day roster out of 2021 spring training, and was expected to back up newly acquired Wilson Ramos.

[17] He was optioned to Toledo after coming off the injured list due to the strong performance of his replacement, Eric Haase.

Greiner was recalled to the major league club on July 19 following an injury to Jake Rogers.

[24] On March 28, 2023, Greiner signed a minor league contract with the Colorado Rockies organization and was assigned to the Triple-A Albuquerque Isotopes.