Carlos Guilen used to be a hot shortstop prospect, whose slick fielding and projectable bat made him one of the key players in the trade that sent Randy Johnson from the Mariners to the Astros. Guillen ended his career as a bulky second baseman who was probably better suited to be a DH. In between, he had a pretty nice career. Guillen announced his retirement on Tuesday.

Carlos Guillen, a three-time All Star and veteran of 14 @MLB seasons, informed the @Mariners today that he is retiring.

— MLB (@MLB) March 6, 2012

Guillen played six years for the Mariners, becoming their everyday shortstop for more than three of those seasons. He hit .264/.335/.383 for the Mariners with 29 home runs in 488 games before he was traded to the Detroit Tigers for Juan Gonzalez (not that one) and Ramon Santiago. Guillen then blossomed for the Tigers, becoming a three-time All Star and finishing 10th in the MVP voting during their 2006 pennant-winning season. Santiago then went back to the Tigers as an extra poke in the eye to the Mariners after his brief fling.

Guillen became one of the most versatile starting players in baseball, playing every infield position as well as several games in the outfield for the Tigers. He had mounting injury concerns, including problems with his left wrist and a calf strain that caused him to miss the Tigers' playoff run.

The Mariners signed Guillen to a minor-league contract in the offseason, so the retirement was something of a surprise this early in spring. Guillen, 36, will finish his career with a .285/.355/.443 (111 OPS+) -- pretty good for a player who picked up more than half of his at-bats as a middle infielder.