Bautista had been designated for assignment by Detroit on June 20 after being squeezed out of a role in the bullpen upon the return on Joel Zumaya. In exchange for Bautista, the Pirates sent Minor League pitcher Kyle Pearson over to the Tigers.
"It's another low-risk [acquisition] with the potential to have a medium-to-high upside," general manager Neal Huntington said. "There's a chance to have a real good return for us. It's a very good arm that we don't have a whole lot of."
Triple-A outfielder Kevin Thompson was given his unconditional release in order to clear a spot on the Pirates' 40-man roster for Bautista. Pittsburgh will also have to make a second roster move to open a spot for the righty on the 25-man roster, but won't do so until Bautista joins the Pirates, which he is expected to do in time for Thursday's game.
Though Bautista spent the season pitching in a variety of roles for the Tigers, which included some time as the team's right-handed setup man with Zumaya and Fernando Rodney injured, the Pirates intend to start out using him in a middle-relief role.
Bautista made 16 appearances for the Tigers this season, allowing seven earned runs in 19 innings. However, he struggled with his control, issuing 14 walks while striking out just 10 in his first season with Detroit. If the Pirates can remedy those control issues, though, they will have a 27-year-old right-hander with an upper-90s fastball and a biting breaking ball.
"If we can reach him and help him throw more strikes, we could have a guy who is pitching in the middle to pitch in the back end," Huntington said. "It's our thought that he's a nice addition and a nice upgrade over what we currently have."
Bautista missed almost the entire month of May, when he went on the disabled list with right shoulder tendinitis. He had been used just three times -- all in mop-up situations -- since returning. However, Huntington said that Pittsburgh scouts were in the stands for two of those appearances and are confident that Bautista's power arm will not be compromised moving forward.
The acquisition of Bautista comes during a week in which the Pirates were known to be scouring the market for a potential starter for the weekend. Though Bautista has made 21 of his 51 career appearances as a starter, his arm is not built up to the point where he will be considered for either Friday or Saturday's spot start.
A decision for Friday's starter is expected to come following Thursday's game, while Saturday's starter will be announced postgame on Friday.
As for the corresponding roster move set to come, Bautista is likely to take the place of right-handers T.J. Beam or Franquelis Osoria, both of whom have assumed middle-relief roles. Though Beam would seem to be the most likely to go, considering he was just called up on Sunday, the fact that Osoria has struggled mightily in recent weeks may be reason enough to send him back to Triple-A for a while.
Osoria has allowed 17 earned runs in his past 16 2/3 innings and has made a scoreless appearance just twice in his past 11 outings.
The Pirates' decision to part ways with Thompson doesn't come as much of a surprise, considering their bevy of outfield talent at the Major League and Minor League level. Furthermore, Thompson broke the hamate bone in his left hand. The surgery will likely force Thompson, who will be out of options after this year, out for the rest of the Minor League season.
The Pirates will be responsible for paying the remainder of his Minor League contract, as well as for all the medical expenses related to his hand injury.
Pearson was a fourth-round selection by the Pirates back in the 2003 First-Year Player Draft and started the season with Double-A Altoona before being demoted to Class A Lynchburg. The right-handed reliever was a combined 1-1 with a 6.85 ERA in the Minors this season.
Jenifer Langosch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.