Grullon will make his first career start in the first game of Tuesday's doubleheader against the Nationals.
Grullon will catch and bat eighth. The 23-year-old has been up for all of September but has made just a single plate appearance. He could get a few more opportunities to audition for the backup catcher job next season with J.T. Realmuto dealing with a sore knee. Grullon had long been seen as a defense-first prospect but has improved his stock over the last two seasons, hitting 21 homers in both campaigns while producing above-average batting lines. He's still unlikely to be anything more than a backup as long as he remains in the same organization as Realmuto.