Source: Brian Fuentes a Red Sox target

BOSTON -- With the ranks of available relievers rapidly thinning, the Boston Red Sox have their sights focused on three pitchers, according to one baseball source: left-hander Brian Fuentes and right-handers Jesse Crain and Matt Guerrier. All pitched for the Minnesota Twins last season, though Fuentes did not arrive until Aug. 27 in a waiver deal with the Angels.

At least nine relievers have come to terms with new teams or accepted salary arbitration with their former teams, including three left-handers: Scott Downs and Hisanori Takahashi, both of whom were signed by the Angels, and Dennys Reyes, who signed with the Phillies.

The market for relievers, non-closer variety, was set by the Detroit Tigers when they signed Joaquin Benoit to a three-year, $16.5 million contract. Downs, whom the Sox had targeted, also signed a three-year deal, for $15 million with the Angels, who surrendered a second-round draft pick to Toronto for him (The Angels' first-round pick was protected).

The other relievers who have signed: Koji Uehara, 1 year, $3 million, Orioles; J.J. Putz, 2 years, $10 million, Diamondbacks; Takahashi, 2 years, $8 million; Jason Frasor, accepted arbitration with Blue Jays; Frank Francisco, accepted arbitration with Rangers; Jose Contreras, 2 years, $5.5 million, Phillies; and Reyes, 1 year, $1.1 million.

The Red Sox were not willing to go to three years on Downs, according to a source. Like Downs, Guerrier is a Type A free agent, but the Twins did not offer arbitration, so compensation is not required. Crain and Fuentes are both Type B free agents.

A brief snapshot of the three:

Guerrier: The right-hander led the American League in appearances in 2008 and 2009, and made 74 appearances last season, with a 3.17 ERA and ERA-plus (adjusted for ballpark) of 131. He held opposing hitters to a .219 average, averaged 5.3 strikeouts per 9 innings pitched, and 2.8 walks per 9 innings. His WHIP (walks plus hits per inning pitched) was 1.099. The 32-year-old Guerrier, who was paid $3.1 million last season, is a sinker-slider pitcher who also throws a curve and changeup.

Crain: The right-hander made 71 appearances last season, with a 3.04 ERA and ERA-plus of 137. He held opposing hitters to a .215 average, averaged 8.2 strikeouts per 9 innings pitched and 3.6 walks per 9. His WHIP was 1.176. Crain has a power arm, with a four-seamer he can throw in the mid-90s. He also features a sinker and slurve, a hybrid curve-slider. Crain, 29, was paid $2 million last season.

Fuentes: The left-hander made 48 appearances last season, with a 2.81 ERA and an ERA-plus of 147. He held opposing hitters to a .181 average; lefties batted just .128 (6-for-47). He averaged 8.8 strikeouts and 3.8 walks per nine innings; his WHIP was 1.063. Fuentes may still be looking for a chance to close. He led the AL in saves for the Angels in 2009 with 48. Fuentes' best pitch is a changeup. He also throws a slider to get left-handed hitters out and a backdoor slider to righties. The 35-year-old Fuentes won't come cheap. He was paid $9 million in 2010.

While these three pitchers appear to be Boston's primary targets, the team is looking at other options as well, including Andrew Miller, the left-hander it acquired by trade from Florida last month, then nontendered.

Gordon Edes covers the Red Sox for ESPNBoston.com. Follow him on Twitter.