CLEVELAND -- The Indians took a chance on Brendan Donnelly last winter, signing him to a Minor League deal when he was six months removed from Tommy John elbow reconstruction surgery in the hope that he could rehab in their system and return to late-inning relief prominence.

The results of the Donnelly experiment, thus far, are 15 relief appearances in August and September in which the right-hander put up a 1-0 record and 8.56 ERA in 13 2/3 innings.

If there is a next step in this relationship, it will have to be negotiated, because the 37-year-old Donnelly filed for free agency Thursday -- the first day eligible free agents were allowed to file. The Indians have 15 days of exclusive negotiating rights with Donnelly before he can talk to other clubs.

The Tribe is searching for bullpen help for next season, but general manager Mark Shapiro hasn't announced whether he feels Donnelly will be part of the '09 mix. The Indians are in a similar situation with Juan Rincon, who was given a chance with the Tribe after he was cut by the Twins midseason. Rincon is also expected to file for free agency in the coming days.

"Those are guys who showed some glimpses of pitching effectively," Shapiro said of Donnelly and Rincon earlier this month. "They are guys we'll maintain a dialogue with this winter."

Donnelly rehabbed in Winter Haven, Fla., for the first half of the season and joined Triple-A Buffalo on July 21. He went 1-0 with a 1.50 ERA in six outings for the Bisons before his contract was purchased by the Tribe on Aug. 8.

Though his ERA was inflated in his short time with the Indians, it's worth noting that nine of Donnelly's 12 appearances were scoreless. Five of the 13 runs he allowed came in a single outing in Baltimore on Aug. 11.

It's possible the Indians will let the 15-day window pass without signing Donnelly but consider him an option to sign later in the offseason.

Donnelly is a combined 26-9 with a 3.12 ERA in his career with the Angels, Red Sox and Indians. He was a dominant setup man for the Angels earlier this decade, making the AL All-Star team in 2003.

Donnelly is eligible for free agency despite having slightly less than six years of big league service time. His free-agent eligibility was negotiated into his Minor League deal with the Tribe.