SEATTLE -- Dontrelle Willis has retired, the Baltimore Orioles announced on Monday afternoon, ending an up and down Major League career for the left-handed pitcher nicknamed "D-Train."

Willis, 30, signed a Minor League deal with the Orioles this spring as a lefty specialist. He returned to a starting role after a dispute with the organization regarding a forearm strain he believed came from working out of the bullpen.

Willis made one start for Triple-A Norfolk upon returning to the club, allowing four runs and six hits in 2 2/3 innings. Willis went 0-3 with an 8.53 ERA in four appearances for the Tides, allowing eight runs (six earned) and 10 hits in 6 1/3 innings. He walked four and struck out four.

"It's kind of sad, in a way, because I know how good he was," Orioles manager Buck Showalter said. "I look at it from the game of baseball -- we'll see what the future holds for him -- [and] appreciate him giving it another shot with us."

Willis won the National League Rookie of the Year Award with the Marlins after going 14-6 in 2003. Two seasons later, he went 22-10 with a 2.63 ERA and finished second in the NL Cy Young Award voting. But Willis' career took a downturn, as his ERA shot up to 5.17 in '07 and never came back down to the levels he posted early in his career. He struggled with the Tigers and Reds, for whom he made his final appearance in the big leagues in 2011. He finishes with a 72-69 record for his nine-year career

Willis was released by the Phillies in Spring Training before being signed to a Minor League deal by Orioles executive vice president of baseball operations Dan Duquette.