The Diamondbacks signed Kubel to a two year contract worth $16 million preceding the 2012 season. The club holds a team option worth $7.5 million on Kubel for 2014, and the buyout will cost them $1 million.
Prior to his tenure in Arizona, Kubel spent 8 years in the Minnesota Twins organization, splitting his playing time between the outfield and designated hitter positions. He was worth 4.6 WAR as a Twin, with a career year coming in 2009 when he hit .300/.369/.539 with a 137 OPS+, 28 home runs, 103 RBIs, and a 24th place MVP finish. As a Diamondback, Kubel has played primarily left field, and posted an above-average .253/.327/.506 line in 2012. He also set career-highs in home runs (30) and walk rate (10%) while posting a .352 wOBA last year. This year, he has been wildly disappointing, hitting just .220/.288/.324 with a 63 wRC+ and .270 wOBA.
John Sickels ranked Holmberg the 5th best prospect in the Diamondbacks organization entering the season, projecting him as a "workhorse inning-eater type." He has a 2.66 ERA in over 152 innings for Double-A Mobile this season. The lefty is slated to make his major league debut tonight against the San Diego Padres.