Kolarek has struggled this spring and is in danger of losing his spot in the bullpen, Ken Gurnick of MLB.com reports.
Kolarek gave up four runs in two-thirds of an inning Sunday, bloating his ERA to 15.43. Although the southpaw pitched well last season -- he posted a 3.27 ERA and 1.16 WHIP in 80 games between Tampa Bay and Los Angeles -- there is no guarantee that he will break camp with the big club given his Cactus League struggles.