Manager Jim Leyland says he's the sixth starter in a five-man rotation, but they couldn't afford to send him down to Triple-A Toledo for more innings because he's so valuable in the bullpen.
"The fact of the matter is, he was our best option for our team right now," Leyland said, "We saw signs of that last night and at other places this year. He's done a good job."
Smyly has made 10 relief appearances when throwing more than 30 pitches, which is tied for the Major League lead, although he's the only one with an ERA under 4.00, at 1.95. He's also second in the Majors with 41 2/3 innings out of relief.
One reason for Smyly's success is the use of his slider. Opposing hitters have a .128 slugging percentage against the pitch, the third lowest in the Majors, according to STATS.
Leyland says he won't pitch Smyly for the next two days because he threw 33 pitches in Monday's 5-1 victory against the Orioles.
"He's actually responded really good in regards to bouncing back [between appearances in the bullpen]," Leyland said. "He's starting to get used to that a little bit. And I will assure you he will tell me today that he can probably go today, and definitely tomorrow, but I'll watch that. Maybe in an emergency tomorrow if I was convinced, but I don't think so."
Jason Beck is a reporter for MLB.com. Read Beck's Blog and follow him on Twitter @beckjason. Bobby Nightengale is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.