Rumor -- soft rumor, if you will -- has it that the Cardinals, even after paying the going rates on Dexter Fowler, may not be done when it comes to splash free agent signings. Specifically, veteran slugger Edwin Encarnacion may be of interest to play first base.

It's not hard to see the appeal. Over the last five seasons, he's put up an OPS+ of 146 while averaging a whopping 44 home runs per 162 games played. In 2016, he took a small step back on a rate basis (133 OPS+) while still cranking lots of homers. Going into his age-34 season, Encarnacion's best days are very likely behind him, but his baseline is such that he can suffer some age-related decline while still being a heart-of-the-order fixture.

On the need side of things, the Cardinals last season got a line of .237/.317/.442 from their first basemen, while the league average at the position was .259/.338/.453. That's a production deficit, obviously. To remedy that, the Cardinals at present are poised to make Matt Carpenter the regular first baseman -- a decision that at once endorses Carpenter's bat and condemns Matt Adams' ability to stay healthy and productive over a full season.

An Encarnacion signing, however, would push Carpenter back to third base (and Jedd Gyorko back to the bench), and that's a potential problem. Carpenter, now on the wrong side of age 30, can still produce at the plate, but he's been a liability in the field for some time. Pair him with Aledmys Diaz at shortstop, who has a promising bat but looks stretched defensively, and you've got a fairly porous left side of the infield.

That's a potential issue for the Cardinals, perhaps to an even greater extent than it would be an issue for any team. In 2016, for instance, the Cards' pitching staff led all of baseball in groundball percentage while grading out as middle of the pack in terms of strikeout percentage. In other words, St. Louis pitchers give their infield defense a workout -- and will likely continue to do so even without Jaime Garcia -- and don't miss bats all that often. Yes, a full season of Alex Reyes in the rotation will presumably help matters on the strikeout front, but this will still be a staff with strong groundball tendencies.

That's the potential cost of adding Encarnacion -- Carpenter, another year into his defensive decline phase, as the everyday third baseman, and an even larger dose of Diaz at short (he played just 106 games at short in 2016). To be sure, the near-term upgrade on offense likely makes the defensive hit worthwhile, even given the proclivities of the St. Louis staff. However, the defensive downgrade eats away a bit at the advantage that Encarnacion would otherwise confer.

The way ahead in the event of an Encarnacion-to-St. Louis signing? More infield over-shifts, possibly. This is of course an era of very active defensive scheming. Fielders are positioned and repositioned throughout an inning based largely on accurate tracking of the hitter's batted-ball tendencies. The Cardinals, while being slow to adopt the strategy, have drastically ramped up use of the shift in recent seasons:

SeasonCardinals' shifts on balls in play

(Data via Baseball Info Solutions)

As you can see, the Cardinals have gradually employed more and more shifts, save for a slight decline in 2015. Last season, they more than doubled their previous total. So that's good. However, put that 2016 figure in a larger context: Those 813 shifts ranked just 18th in the league. In other words, the Cardinals are shifting less than the average bear these days.

To be sure, it's not necessary to shift aggressively in order to be a good team defensively (the Cubs, for instance, shifted the fewest times of any team in 2016). However, it's a good way to overcome range limitations, particularly in the infield. The 2017 Cardinals, especially if they sign a new first baseman, figure to have range limitations on the critical left side.

So the best way forward for the Cardinals may be to take the plunge on Encarnacion -- they've already forfeited their highest draft pick by signing Fowler -- and then devote organizational brainpower to shifting more in order to paper over the defensive weaknesses of Carpenter and Diaz. That way, they can perhaps get the most out of the offensive upgrade that Encarnacion would provide.

So, yes, Encarnacion is a fit in St. Louis -- guys with 40-homer power are typically a fit on any roster at the right price. He's not a perfect fit, though, because of the defensive hit that would cascade down the roster. More aggressive shifting could lessen that concern a bit, at least for now.