Thompson was optioned to Triple-A Rochester, the Minneapolis Star Tribune reports.

Thompson looked to be the top lefty in the Minnesota bullpen after a strong first two months of the season (3.42 ERA), but he's fallen apart with nine earned runs in 8.1 innings since June 1. Overuse may have been an issue, as he had an AL leading 41 appearances in Minnesota's first 82 games.

Aaron Thompson retired the only batter he faced on a double play grounder to record his ninth hold in Saturday's win over Kansas City to lower his ERA to 5.01.

Thompson looked to be the top lefty in the Minnesota bullpen after a strong first two months of the season, but he struggled with a 10.8 ERA in June. He has just 4.7 K/9 and is walking too many batters with a 3.1 BB/9. He has held left-handed batters to a .481 OPS, so the Twins will need to limit his exposure to right-handed batters for him to be effective.

Thompson retired the only batter he faced in Friday's loss to Toronto to lower his ERA to 3.42.

Thompson has become Minnesota's top lefty setup man and has only allowed a run in six of 25 appearances. However, he has just a 14:7 K:BB ratio in 23.2 innings. He's unlikely to sustain his early success with just a 5.3 K/9.

Thompson threw two scoreless innings in Sunday's win over Cleveland to lower his ERA to 0.87.

Thompson has become the top lefty in the bullpen with Brian Duensing on the DL. He's given up just two walks and four hits in 10.1 innings this season.

Thompson was recalled from Triple-A Rochester and added to Minnesota's 25-man roster, MLB.com reports.

Thompson may only be in the majors for a few weeks as Minnesota's bullpen may be in flux in April. Thompson will be the third lefty in the bullpen, so he may not be used in a lot of high-leverage situations.

Thompson did not make the Opening Day roster, LaVelle E. Neal of the Minneapolis Star Tribune reports.

With Thompson headed to Triple-A Rochester, Caleb Thielbar appears to have won the final spot in Minnesota's bullpen. Should the Twins have need of a lefty reliever, Thompson will likely be the first man called up.

Thompson is in the running for one of Minnesota's final two bullpen spots, the Minneapolis Star Tribune reports. He has a 2.84 ERA with a 6:2 K:BB ratio in 6.1 innings this spring.

He's probably a long shot since he'd have to win a job over Caleb Thielbar as a second left in the bullpen. Still, his 8.8 K/9 in Triple-A last year suggests he could be an effective lefty specialist in the majors.

Thompson's contract was selected from Triple-A Rochester on Saturday, Mike Berardino of the St. Paul Pioneer Press reports.

In 15 second half outings at Rochester, Thompson has struggled, to say the least, posting a 9.22 ERA, 2.12 WHIP, and 12:11 K:BB in 13.2 innings. Considering he hasn't fared much better in four major league appearances -- 7.04 ERA in 7.2 innings -- he'll likely only be utilized by the Twins in low-leverage situations.

Twins re-signed LHP Aaron Thompson to a minor league contract.

Thompson was suspended for the first 50 games this past season for violating baseball's drug policy, but he returned to post a 2.76 ERA over 58-plus frames on the farm. The southpaw will compete for a bullpen spot in spring training.

Twins' minor league left-hander Aaron Thompson will be suspended 50 games for violating baseball's drug policy.

The commissioner's office has yet to make an official announcement on the suspension, but Twins' general manager Terry Ryan said Saturday that he tested positive for recreational drug use, not performance-enhancing drugs. Thompson, 25, signed a minor league deal with the Twins this winter after spending last season in the Pirates' organization.

Twins signed LHP Aaron Thompson to a minor league contract.

He also receives an invite to spring training. Thompson, who was claimed off waivers by the Bucs from the Nationals last December, made four appearances with the big club in August and September. While his command improved in the minors this season, the 24-year-old southpaw is missing less bats than ever before. He likely won't make an impact with the Twins, but Minnesota is making sure it improves a putrid Triple-A Rochester team from this past year.

Pirates sent LHP Aaron Thompson outright to Triple-A Indianapolis.

Thompson, who was claimed off waivers from the Nationals last December, made four appearances with the big club in August and September. While his command improved in the minors this season, the 24-year-old southpaw is missing less bats than ever before.

Pirates recalled LHP Aaron Thompson from Triple-A Indianapolis.

Thompson threw 4 1/3 scoreless innings in his major league debut earlier this season against the Brewers. He'll function as a long reliever this month for Pittsburgh.

Pirates optioned LHP Aaron Thompson to Triple-A Indianapolis.

Thompson pitched well in his major league debut Wednesday, tossing 4 1/3 scoreless innings in a spot start against the Brewers. The 24-year-old southpaw could rejoin the Pirates in September.

Aaron Thompson pitched 4 1/3 scoreless innings against the Brewers in his major league debut Wednesday.

Thompson was pulled after getting into trouble in the fifth, so he didn't get the chance to get the win in what was a 2-0 game. He did, however, escape with a perfect ERA after Jason Grilli stranded both runners he inherited. Thompson wasn't guaranteed anything more than the one spot start, but perhaps he'll get a chance to stick around after the solid showing.

The Pirates have summoned left-hander Aaron Thompson from Triple-A Indianapolis.

The Pirates haven't made an official roster move, but he could be a candidate to start Wednesday or pitch out of the bullpen. The 24-year-old southpaw has a 4.63 ERA and 60/22 K/BB ratio over 95 1/3 innings this season between Double-A Altoona and Triple-A Indianapolis. It's unlikely he'll be fantasy relevant.

Pirates sent LHP Aaron Thompson outright to Double-A Altoona.

Thompson was designated for assignment last week to clear a spot for Chase d'Arnaud on the 40-man roster. The 24-year-old southpaw has a 4.97 ERA and 43/18 K/BB ratio over 67 innings at the Double-A level this season.

Pirates designated LHP Aaron Thompson for assignment.

Space was needed on the 40-man roster for Chase d'Arnaud. Thompson, 24, was struggling mightily for Double-A Altoona this season, posting a 4.97 ERA and 1.43 WHIP in his first 67 innings of work. It's a possibility he'll clear waivers and end up back with the Bucs.

Pirates claimed LHP Aaron Thompson off waivers from the Nationals.

Thompson entered the 2010 season ranked as the No. 12 prospect in the Nationals organization, according to Baseball America, but he posted an underwhelming 5.65 ERA over 27 starts between Double-A and Triple-A, averaging 6.3 K/9 and 3.6 BB/9. It was a big step back for the former 2005 first-round pick, but he's a worthy gamble for the pitching-hungry Pirates.