DETROIT -- It didn't take long into this struggling start for the Tigers to pull off a major swap. All they had to do was shuffle Miguel Cabrera and Carlos Guillen across the infield.

In a brief announcement after Tuesday's win over the Rangers, manager Jim Leyland said he was making the switch full-time. Cabrera, who has made four starts at first base this season while Guillen has either been at designated hitter or off, will stay at first full-time. Guillen, meanwhile, will move to third base for the first time since 2003.

"We think at this particular time it gives us a better team," Leyland said. "So that's what we're doing."

That was the extent of the analysis, but the performances to date in the field provided the evidence.

When the Tigers traded for Cabrera in December, team officials said from the outset that he would be their everyday third baseman. With that in mind, infield coach Rafael Belliard worked with him extensively during Spring Training on his fielding.

In 14 starts at third, however, Cabrera has five errors in 50 total chances. Though he has had some highlight plays, his miscues have included fielding plays and throws. He made his first professional appearance at first base on April 12 at Chicago and has seemingly adapted well.

After the game, Cabrera said he was OK with the move. Leyland broke the news to them during pregame batting practice.

Up until now, Cabrera's time at first has been as a fill-in, while the Tigers have shuffled their lineup around various injuries. Each time, Brandon Inge has filled in at his previous position at third. With the more permanent move, however, Guillen becomes the full-time third baseman, a role he filled early in his career in Seattle when Alex Rodriguez was still a Mariner and for other points beyond that.

Guillen essentially became a first baseman down the stretch last season as a way to ease the wear and tear on his knees after nearly four seasons as Detroit's everyday shortstop. While his range has been a benefit at first, he has had trouble this season handling the footwork. At one point earlier this season, he was risking putting his foot in the baseline when fielding throws. He had one error this season when he dropped a throw April 6 against the White Sox.

Guillen said he was not surprised by the move, suggesting he had pondered the possibility before.

"It's fine for me and it's good for this team," Guillen said.

Guillen has played 100 games at third base over the course of his career. All of those came while he was with the Mariners, including 32 games during his final season in Seattle in 2003.