Whether or not Troy Percival goes on the 15-day disabled list tomorrow, it seems possible the Rays will summon Grant Balfour to shore up their relief corps.

Percival figures to miss at least a few days after leaving today’s game with tightness in his left hamstring and the Rays don’t want to be short in the bullpen. They could make room for Balfour by optioning down Ben Zobrist, who was likely to get the ax anyway when Willy Aybar returned, and waiting a day or two on Aybar if necessary while they see how Percival responds to treatment.

“I really don’t know where it’s going to take us at this point,” said Joe Maddon.

Balfour, who lost out to Scott Dohmann in a spring training duel for the final bullpen spot, has been dominant for Durham this season. The 30-year-old is 1-0 with a 0.38 ERA in 15 appearances, collecting eight saves while allowing just five hits and striking out 39 in 23 2/3 innings. He posted a 6.14 ERA in 22 relief appearances for the Rays last year after coming over from Milwaukee for Seth McClung.

Though the Rays are hopeful Percival will be able to avoid a DL trip, his inability to finish off the game was not a good sign.

“I knew he was hurting, because he did the same thing in Oakland and he stayed out there and he got the job done,” said Dan Wheeler, his likely replacement as the closer. “That’s Percy right there. … For him to take himself out of the game, it made me worry a little bit.”