DETROIT -- Charlie Furbush, a key member of the Mariners' bullpen as their left-handed setup man, will likely need a Minor League rehab stint before rejoining the club as he continues working his way back from left biceps tendinitis.
Furbush was eligible to come off the 15-day disabled list on Thursday, but he's still a week or more away from returning and he's yet to throw off on a mound since his last outing with Seattle on July 7.
Furbush threw a flat-ground session on Wednesday at Safeco Field, and he will repeat that after the Mariners return home on Friday before likely throwing a bullpen session off the mound at some point next week.
"His throwing program is going pretty good," manager Lloyd McClendon said. "He felt real good. He'll probably do a bullpen when we get home and we'll see where we are."
Though the initial hope was Furbush would be able to rejoin the Mariners without needing any Minor League rehab, that appears to have changed as his return was pushed back.
"It's been so long now, he needs to go out and get some action," McClendon said.
Seattle could use Furbush's help in a bullpen that has struggled to duplicate last year's success. Furbush has a 2.08 ERA and 0.65 WHIP in 33 games, he's stranded all 16 runners he's inherited and opposing batters are hitting just .122 against him.
"He's that dominant lefty in big situations that we didn't have in New York and a couple times here," McClendon said prior to Thursday's series finale against the Tigers. "It's obviously affected us."
Even with Furbush out, the Mariners still have three lefties in their bullpen with the addition of Rule 5 Draft pick David Rollins, who came off an 80-game suspension on July 4 and has posted a 9.00 ERA in six outings. Rollins has had a couple rocky outings, but he pitched 2 1/3 scoreless innings in Wednesday's 9-4 loss after starter Mike Montgomery lasted just 2 2/3 innings.
"Rollins did a great job and really saved us. He's getting better," McClendon said. "He's a young kid. He's inexperienced at this level. We've tried to put him in situations where he's got a chance to be successful and get his feet wet. But he's doing OK.
"He struggles mostly when we bring him in in the middle of an inning. When he starts an inning, he's pretty good. And I think that's just the experience factor. But his stuff is plenty good to pitch at this level."
Rollins has to remain on the 25-man roster for the remainder of the season or be offered back to the Astros, so the Mariners face a decision with him when Furbush does return. Veteran Joe Beimel and Vidal Nuno, acquired from the D-backs in the Mark Trumbo trade, are the other two southpaws.
Nuno was sent down to Tacoma on July 4, but he was recalled when Furbush went on the DL on July 9, and he has posted a 2.16 ERA in 16 2/3 innings over 15 outings. The Mariners were going to stretch Nuno out into a starting or long relief role, but he's stepped back into a setup situation in Furbush's absence.
"Ideally, you'd like to have him as your long guy, but he's done a nice job in Furbush's role," McClendon said.