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Talk of moving Joe Mauer from catcher to another position has been common since 2004 when his rookie season was ruined by knee surgery and got loudest when he spent half of 2011 on the disabled list, but recently he's been so healthy and productive that it's become little more than a whisper. Unfortunately the volume is rising again because Mauer is on the DL and out indefinitely after suffering a concussion while catching last week. It's a very complicated question.

Since coming back from his injury wrecked 2011 season Mauer has hit .321 with a .410 on-base percentage and .460 slugging percentage in 1,149 plate appearances. Among all catchers with at least 600 plate appearances during that two-year span Mauer leads MLB in on-base percentage, ranks second in batting average a few points behind Yadier Molina, and is tied with Molina for second in adjusted OPS+ behind Buster Posey.

However you slice it Mauer has been one of the three best-hitting catchers in baseball over the past two years and his combined .321/.410/.460 mark during that time is nearly identical to his .323/.405/.468 career line. And looking at his career totals paints Mauer in an even better light, because he's maintained his level of excellence for a decade. Here are the hitting leaders among active catchers with at least 1,000 career plate appearances:

BATTING AVERAGE            ON-BASE PERCENTAGE         SLUGGING PERCENTAGE
JOE MAUER         .323     JOE MAUER         .405     Buster Posey      .497
Buster Posey      .312     Buster Posey      .379     Brian McCann      .477
Yadier Molina     .285     Carlos Santana    .365     JOE MAUER         .468
A.J. Pierzynski   .284     John Jaso         .364     Carlos Santana    .446
Jonathan Lucroy   .281     Ryan Hanigan      .364     David Ross        .442

Mauer has the best batting average by 11 points over Posey and at least 38 points over everyone else. Mauer has the best on-base percentage by 26 points over Posey and at least 40 points over everyone else. And he ranks third in slugging percentage behind Posey and Brian McCann. Add it all up and here are the active catching leaders in overall offensive production according to OPS, adjusted OPS+, and weighted on-base average:

OPS                        ADJUSTED OPS+              WEIGHTED ON-BASE
Buster Posey      .876     Buster Posey       146     JOE MAUER         .377
JOE MAUER         .873     JOE MAUER          135     Buster Posey      .376
Brian McCann      .827     Carlos Santana     128     Brian McCann      .355
Carlos Santana    .811     Brian McCann       118     Carlos Santana    .353
Miguel Montero    .780     John Jaso          114     Miguel Montero    .340

In terms of career-long production Mauer and Posey are the players with an argument for being the best-hitting catcher in baseball and Molina enters the mix if the most recent two seasons are given more weight. Mauer has also been an asset defensively, throwing out 43 percent of steal attempts this season and 33 percent for his career compared to the MLB average of 25 percent. And for whatever value you choose to place in Gold Glove awards Mauer has three of them.

Whether you focus on recent performances or career-long track records Mauer stands out as one of the two or three best catchers in all of baseball and certainly has a strong argument for being the best catcher considering he's maintained elite status for much longer than Posey or Molina. However, if you take his 2012/2013 numbers and make those same comparisons to first basemen (and designated hitters) instead of catchers Mauer slides down the rankings a bit:

BATTING AVERAGE            ON-BASE PERCENTAGE         SLUGGING PERCENTAGE
Joey Votto        .324     Joey Votto        .451     David Ortiz       .589
JOE MAUER         .321     JOE MAUER         .410     Chris Davis       .585
David Ortiz       .318     David Ortiz       .406     Edwin Encarnacion .546
Allen Craig       .310     Prince Fielder    .383     Joey Votto        .533
Billy Butler      .303     Paul Goldschmidt  .378     Paul Goldschmidt  .518
                                                      ...
                                                      JOE MAUER         .460

If you compare Mauer to first basemen rather than catchers he falls behind Joey Votto as his position's king of batting average and on-base percentage, although Mauer still ranks second in both categories for 2012/2013. However, the big change is that while slugging .460 gets Mauer ranked among the top half-dozen catchers for 2012/2013 it would place just 20th among first basemen and designated hitters during that same time. Here's a look at overall production:

OPS                        ADJUSTED OPS+              WEIGHTED ON-BASE
David Ortiz       .995     David Ortiz        166     Joey Votto        .419
Joey Votto        .985     Joey Votto         163     David Ortiz       .415
Chris Davis       .941     Chris Davis        151     Chris Davis       .396
Edwin Encarnacion .922     Edwin Encarnacion  148     Edwin Encarnacion .391
Paul Goldschmidt  .896     Paul Goldschmidt   141     Paul Goldschmidt  .382
...                        ...                        ...
JOE MAUER         .870     JOE MAUER          140     JOE MAUER         .379

Mauer narrowly misses cracking the top-five first basemen in OPS, adjusted OPS+, and weighted on-base average for 2012/2013, ranking sixth in all three categories. Beyond focusing on where he'd stand relative to the truly elite players at each position, his place relative to the average at each position would also fall. Mauer has an .870 OPS for 2012/2013, which is 22 percent above average for a catcher versus 12 percent above average for a first baseman.

As a catcher Mauer is arguably the best at his position and no worse than the top three, producing 20-25 percent more offense than an average player. As a first baseman he'd have zero claim to being the best at his position and realistically slot somewhere in the 5-10 range, producing 10-15 percent more offense than an average player. Or, put another way: By moving from catcher to first base he'd go from elite to merely very good and All-Star spots might be hard to come by.

Of course, it's not as simple as looking at where his production would rank at a new position. By moving away from catcher and avoiding the daily physical toll Mauer should in theory be able to stay healthier, play more games, and increase his offensive output. So perhaps instead of being a top-three catcher for 135 games he'd be a top-eight first baseman for 155 games. And maybe he'd go from a top-eight first baseman to a top-five first baseman by not wearing down as much.

None of that is set in stone, however. For one thing simply playing first base or even designated hitter doesn't make someone immune to injuries and wearing down, as Justin Morneau has sadly demonstrated. There's also no guarantee that moving out from behind the plate will automatically increase Mauer's output at the plate. Mauer's odds of staying healthy and upping his production should be better at a position other than catcher, but it's impossible to know for certain.

Having a great-hitting catcher impacts a lineup a few ways, because in addition to being a strong bat his presence also keeps the team from having to use a weak-hitting catcher and leaves a spot open for another strong bat who doesn't have to be much of a defender at first base, an outfield corner, or designated hitter. If the Twins move Mauer they'd have to find a new catcher who'd be a sizable downgrade offensively and they'd have one less spot for a defensively challenged bat.

In terms of in-house options to replace Mauer at catcher Ryan Doumit is under contract for 2014, Chris Herrmann is holding his own as a rookie, and Josmil Pinto is a step away from the majors at Triple-A. Of course, Doumit catches like a designated hitter, Pinto might end up at designated hitter, and Herrmann is a 25-year-old with a .372 career slugging percentage in the minors. It's not a terrible set of options, but that mostly just speaks to the overall weakness of the position.

Another potential issue with a position switch is that assuming Mauer's production declines as he gets deeper into his thirties like the standard aging curve he'd remain an above-average catcher for much longer because the bar is so low at the position. First base is a much different story, as a decline-phase Mauer hitting, say, .285 with 10 homers and a .750 OPS, would drop to the bottom of the positional pile pretty quickly. He's signed through age 35, in 2018.

Ultimately, though, here's why the speculation about Mauer changing positions has started up again after being dormant for a while: Catching puts players at much higher risk for concussions and none of the above numbers will mean anything if Mauer's career is derailed by brain injuries like Morneau and Corey Koskie before him. Mauer is a great catcher and might "only" be a good first baseman, but a good first baseman is more valuable than a catcher disabled by brain trauma.

This is an impossible question to answer definitively, because brain injuries are so unpredictable that even MLB organizations with $100 million payrolls and doctors with high levels of expertise and decades of experience struggle to effectively diagnosis and treat concussions. In general the amount of Mauer's value that comes from being a catcher and in turn his all-around value are often undersold, but the "should Mauer change positions?" question is no longer just about value.

For a lengthy discussion about a potential Mauer position switch, check out this week's "Gleeman and The Geek" episode.

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