The Red Sox right-hander just doesn't know if it will be against the Florida Marlins or another rehabilitation assignment for Triple-A Pawtucket as he works his way back from shoulder surgery.
Red Sox manager Terry Francona said before Sunday's game against Philadelphia that a decision will be made in the next day or so. Smoltz, who is continuing his comeback from surgery last June to repair a torn labrum, said he could wait.
"What you see before you is not a guy you would see two, three, five years ago," Smoltz said. "I'd be really anxious, probably would have forced a few people's hands and try and convince them I'd be ready a month ago. It's just a lot of understanding of what they want to do."
Smoltz is the only pitcher in major league history with at least 200 victories and 150 saves. He's made five minor-league rehab starts, and allowed four runs and six hits in a six-inning outing Friday night.
He opened the season on the disabled list following shoulder surgery last June. Smoltz agreed to a $5.5 million, one-year deal with the Red Sox in January after 20 seasons with the Atlanta Braves.
Smoltz joked before the AL-best Red Sox went for the three-game sweep in Philadelphia that he could make a spot start for starter Josh Beckett.
"It looks like I'm starting for Beckett today. Oh, you guys didn't hear?" Smoltz said.