BOSTON -- The Tigers should have a better idea in the next couple of days on if and when Fernando Rodney can return. Detroit's injured setup man is scheduled to throw a bullpen session by the end of the week that should further test his right shoulder, which has had on-and-off soreness since the end of February.

Rodney, currently on the 15-day disabled list, threw what head athletic trainer Kevin Rand called a light, easy five-minute session off a mound Wednesday. He was going through his throwing motion to see how it felt, but Rodney wasn't throwing anywhere near game intensity.

"He was kind of going through the motion to make sure that from a delivery perspective, he feels OK," Rand said.

It was progress, because it was at the same point that he felt shoulder pain last week, prompting the Tigers to shut him down for a few days.

Given Rodney's setbacks over the last six weeks, there's no specific timetable for a return. If he can throw his next bullpen session without pain, however, it would allow the Tigers to start the progression toward facing hitters, pitching in rehab games and eventually returning to Detroit, where the bullpen could certainly use him.

The Tigers' other injured setup man, Joel Zumaya, is also making progress. He's currently throwing long toss from up to 120 feet, Rand said, and is on track to throw off a mound around the beginning of May.

"He's doing OK," Rand said. "I'm pleased with the progress."

In the relievers' absence, obviously, the Tigers are moving on. Detroit had four innings of scoreless relief in Wednesday's 7-2 win before three relievers had to eat innings in Thursday's 12-6 loss.

Denny Bautista and Todd Jones were finally able to assume their roles as setup man and closer, respectively, to protect Wednesday's lead. Left-hander Bobby Seay began the seventh inning and retired the leadoff hitter before giving way to Francis Beltran, but Leyland said Thursday he will mix and match in that inning, giving relievers opportunities to show what they have.

"To get to Bautista, it'll be a crapshoot," Leyland said.

With eight relievers on the roster, the Tigers have quantity in options, but that won't last all season. At some point, Leyland said, he'd like to reset the bullpen back to seven, including a second left-hander to go with Seay. That would reduce the roster by two right-handers.

The Tigers have three left-handed relievers at Triple-A Toledo, with Clay Rapada, Aaron Fultz and newly signed Casey Fossum whenever he's back in game shape.