Balester shuttled between the majors and Class AAA Syracuse last season and had a 4.54 ERA in 35 2/3 major league innings, primarily as a long reliever. The Nationals were motivated to move Balester because he has run out of minor league options, while Perry still has one remaining. Essentially, they can do with Perry what they did with Balester last year – toggle him up and down for roster management purposes without the threat of losing him.

Early in his career, the Nationals, and the rest of baseball, anticipated far greater things from Balester. In 2004, the year before they moved to Washington and became the Nationals, the Montreal Expos drafted him in the fourth round. By 2007, Baseball America named Balester, armed with a tall, pitcher’s frame and a 95-mph fastball, the best prospect in the organization.

Balester made his major league debut in 2008, and over the next two seasons, falling in and out of the Nationals’ rotation, Balester went 4-11 with a 5.87 ERA. The team moved him to the bullpen in 2010, a decision he at first resisted, then embraced. Relieving fit his personality – he no longer had to twist his mind in knots thinking about the next start. He just pitched.

Balester thrived once he reached the majors in 2010, but only occasionally matched his best performances in 2011. The Nationals used him as a long man, an unglamorous role Balester performed admirably. In one blowout, the only major league game he pitched in July, he threw 76 pitches.

Balester was quirky, well-liked by teammates. He held long conversations about video games and derived great satisfaction from his mustache, which every November he sported in support of men’s health and prostate cancer awareness.

Now he’ll head to Detroit for Perry, another pitcher who has not met his perceived potential. The Tigers drafted Perry with the 21st overall pick in 2008. He reached the majors quickly, appearing in 53 games in 2009.

Injuries stifled his progress in 2010, when the Tigers twice placed him on the disabled list with right shoulder tendonitis. Last year, he missed most of April with an eye infection.

Perry averages about 95 miles per hour with his fastball, which he mixes primarily with a slider. He could fill a role similar to Todd Coffey, who will likely leave in free agency.

Losing Balester erases one of the final remaining connections between the Nationals and Expos. The only players acquired by the Expos who have continuously played in the organization are believed to be shortstop Ian Desmond, outfielder Roger Bernadina, reliever Atahualpa Severino and minor league infielder Seth Bynum.