Zumaya, who went on the 15-day disabled list a week ago after feeling pain in his right throwing shoulder, threw Sunday for the first time since aggravating the injury last Friday at Yankee Stadium. His arm felt fine, and both he and Detroit officials are optimistic that he should be back pitching soon.
"Joel Zumaya, we think, is going to be able to pitch for us this season," manager Jim Leyland said Sunday.
Head athletic trainer Kevin Rand said earlier this week, after Zumaya took cortisone shots in the front and back of his shoulder, that the right-hander could have a minimal stay on the DL if his shoulder responds well. It's too early for the Tigers to say that for sure, but that seems to be the hope, since Zumaya hasn't been shut down from throwing for long and shouldn't have lost much endurance in his arm.
Zumaya still has to progress from throwing off a mound to facing hitters. Still, it could be worse.
"I'm throwing," Zumaya said. "I could be at home sitting on the couch. It's good right now."
Bonderman threw a mound session Saturday and came out of it feeling fine with his shoulder, which has shelved him for much of the season since undergoing surgery last summer. His next step will be a simulated game against Tigers hitters, likely during their series at Cleveland next weekend.
If that goes well, it shouldn't be a long time before he returns.
"I think Bonderman is probably -- in some way, shape or form -- sooner than later," Leyland said. "I think he's coming along pretty good, but I've learned not to get too excited. But if I was to say right now, I'd say sooner than later, in some capacity."
If the Tigers follow through on their plan to use Bonderman as a reliever, he won't have to be stretched out for long. Leyland, however, didn't have a firm answer on that.
"I can't answer that right now," Leyland said. "We're still a ways away, but I think we're getting close to some action that will tell us if we're close. I guess that's the best way to put it. We think we're getting pretty close, but we'll have to wait until the action starts, and then we'll see how that goes from there."
There's a chance Nate Robertson will pitch the other side of that simulated game next weekend. He threw a nine-minute bullpen session Sunday and got an idea for the first time how much of a difference his surgery made in how his arm feels. Robertson underwent surgery at the beginning of the month to remove four masses from his elbow that had been restricting a nerve.
"Today was the first day where the swelling went down," Robertson said, "and I felt like there was a bit of a difference."
So did bullpen coach Jeff Jones, who saw a little more bite in Robertson's slider and a lot more peace of mind in his head.
"I think there's a big load off his mind once he got those things out of there," Jones said.
All those developments don't mean the Tigers won't continue to look for bullpen help on the trade market. They've had scouts watching teams with relievers on the block including Pittsburgh, which could decide to deal Matt Capps, and San Diego, which appears unlikely to deal closer Heath Bell.
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.