A year ago, the St. Louis Cardinals tried the unorthodox move of switching third baseman Matt Carpenter to second base, a position he had played just 18 innings previously in the majors and never in the minors. Players rarely move up the defensive spectrum, but the risk paid off for the Cardinals as Carpenter played a solid second base -- he rated as league average via defensive runs saved (DSR) -- and had a big year at the plate, hitting .318 and leading the National League in runs, hits and doubles.
Carpenter will move back to third base in 2014, clearing room for rookie second baseman Kolten Wong. That will allow the Cardinals to upgrade defensively at two spots: Carpenter over David Freese at third base and Wong, considered a plus defender, over Carpenter.
With teams opening up camps later this week, here are some other key position changes to watch in spring training:
Joe Mauer, Twins: Catcher to first base
Mauer has started 54 games at first base in his career, but it appears his catching days are over as he takes over for the departed Justin Morneau. It's the right move by the Twins. It appears that rookie catcher Josmil Pinto will be a solid major league regular, and the move will help keep Mauer healthy and his bat in the lineup more often. Plus, he hasn't really been a regular catcher in recent seasons anyway: The past two seasons, he started 73 and 72 games behind the plate. Mauer may not provide the prototypical power you'd like from a first baseman, but his .400 on-base percentage plays anywhere. He's a good enough athlete to be decent with the glove (he's plus-1 DRS at first base in his limited time there).
Carlos Gonzalez, Rockies: Left field to center field
Like the Carpenter move, this one involves a player shifting to a more demanding position. Gonzalez hasn't played any center field the past two seasons, but did play there earlier in his career (187 games started). This one is interesting because Gonzalez's defensive metrics in left field have been all over the place: plus-8 in 2011, minus-13 in 2012, plus-10 in 2013. Gonzalez, who missed time with a finger injury in 2013, underwent emergency appendectomy surgery in January but is expected to be fully ready for spring training. The Rockies did acquire Drew Stubbs and Brandon Barnes in the offseason, two guys who can play center if Gonzalez is deemed lacking in range.
Ryan Braun, Brewers: Left field to right field
All 817 of Braun's games in the outfield have come in left, but he'll move to right as the weaker-armed Khris Davis takes over in left. DRS has rated Braun as a plus fielder over the years in left -- plus-28 runs -- but his arm has rated slightly below average at minus-10 runs. Still, he should be to handle right field, although opposing baserunners will surely test his arm early on.
Carlos Santana, Indians: Catcher to third base
By far the most intriguing position change, this one isn't written in stone, but Santana has played some third base this winter. With Yan Gomes emerging as a plus defensive catcher, the Indians want to keep Santana's bat in the lineup and Lonnie Chisenhall may be out of chances at third base. Santana was originally an infielder in the low minors before switching to catcher, so moving to third base won't be completely foreign to him. Still, the catcher-to-third move is a rare one midcareer, most notably done by Joe Torre, Todd Zeile and Brandon Inge (who had been a shortstop in college). Most likely, Santana settles in as a super-utility guy, filling in at third and first if he's not the full-time DH.
Alex Guerrero, Dodgers: Shortstop to second base
This is the most common position change as shortstops without quite enough arm are shifted to second. In Guerrero's case, he played shortstop in Cuba and will move because Hanley Ramirez is entrenched at short. The Dodgers sent Guerrero to the Dominican Winter League, but early reports on his defense were not good, with stiff hands being the big issue. He played only a few games there, however, so spring training will be a crash course at second base. The Dodgers are banking heavily on Guerrero since the backup appears to be Dee Gordon, who has struggled at the plate the past two years.
Shin-Soo Choo, Rangers: Center field to left field
Choo had been a right fielder with the Indians and then played center for the Reds. He had a huge year offensively but showed a lack of range in center. The Rangers will wisely move him back to a corner slot, with Leonys Martin in center. Even then, Choo may prove to be a below-average defender as his metrics in right field in 2012 were not good (minus-12 DRS).
Miguel Cabrera, Tigers: Third base to first base
The Tigers will have new infielders at all four positions, certainly an interesting twist for a likely playoff team. But they have arguably upgraded defensively at all four spots: Cabrera over Prince Fielder at first, Nick Castellanos over Cabrera at third, Ian Kinsler over Omar Infante at second, and Jose Iglesias over Jhonny Peralta at shortstop. Cabrera isn't a great first baseman, no matter what people try to tell you; he has good hands, but he still moves about as well as a redwood tree.
Rafael Furcal, Marlins: Shortstop to second base
After missing all of 2013, Furcal is hoping to hang on with the Marlins. He hit .264 AVG/.325 OBP/.346 SLG with the Cardinals in 2012, which would be only a minor improvement over the .235/.292/.349 mark the Marlins got from their second basemen in 2013.