He played in Major League Baseball (MLB) for the Minnesota Twins, Arizona Diamondbacks, and Cleveland Indians.

[5] Kubel's play impressed manager Ron Gardenhire enough to warrant a call-up to the majors for the Twins' American League Central Division championship run in September.

[6] Kubel suffered a serious knee injury in the Arizona Fall League later that year, which caused him to miss the entire 2005 season.

[9] He hit well in his return, including a walk-off grand slam against the Boston Red Sox in the 12th inning at the Hubert H. Humphrey Metrodome on June 13, 2006.

[6] Kubel's 2007 statistics showed improvement, as he finished the season with a .273 average, 13 home runs and 65 RBI in 128 games with 418 at-bats.

[11] During the 2008 season, Kubel primarily served as the designated hitter slot due to the acquisition of left fielder Delmon Young from the Tampa Bay Rays.

Kubel finished the season with career highs in batting average (.300), doubles (35), RBI (103), total bases (277), and OPS (.907), and games played (146).

However, due to the defensive shifting resulting from Justin Morneau's ongoing health issues, Kubel settled in as the Twins' right fielder, platooning with Michael Cuddyer.

On April 12, Kubel hit the first home run in a regular-season game at Target Field, helping the Twins christen their new stadium in a 5–2 victory over the Boston Red Sox.

[16] On May 16, Kubel hit a grand slam off legendary closer Mariano Rivera to help the Twins beat the Yankees.

Due to injuries by fellow outfielders Delmon Young,[19] Denard Span,[20] and call-up Jason Repko,[21] Kubel's position was critical to the Twins before finally getting hurt himself and missing all of the month of June.