When you have something good and potentially great in-house, it's wise to keep it around.

Did the Cardinals act too soon in giving their Opening Day shortstop, Paul DeJong, a 6-year contract worth $26 million dollars today? Not at all, and here are five reasons why:

1) DeJong's production can't be denied. In only 108 games last season, he smashed 25 home runs, 26 doubles, and accumulated a .857 SLUG and 122 wRC+ after arriving on May 28. The Illinois University product has legit power and hits both righties and lefties well.

2) DeJong held up over the course of the season. He posted great months in July and August, and finished well in September. Pitchers couldn't quickly solve the kid and his pop didn't disappear.

READ MORE | DeJong, Cardinals agree to multi-year extension

3) The shortstop position may be the most important on a baseball field, and DeJong didn't look too shabby out there. The man has a cannon from short and in just over 767 innings, posted a 1.8 Ultimate Zone Rating. He committed nine errors, but showed a lot of promise and improvement over the course of a season.

4) DeJong was worth 3.0 fWAR to the Cardinals in two-thirds of a season last year. How does that translate out to a full serving? Even with a little regression, DeJong will be a viable asset at a comfortable $4.3 million average annual value. You are getting the kid for six years for less than one year of what the Angels are paying former Cardinal Albert Pujols. That's just a little perspective, so don't think about it too hard.

5) DeJong's production has trended up or held up with each year through the baseball levels of competition. Starting with Palm Beach in 2015, continuing with Springfield in 2016, and a combination of Memphis and St. Louis last year, DeJong's power and sustainability hasn't wavered as the pitching skill has increased.

Now, there is some concern, and it's palpable.

  • DeJong's 30% strikeout rate is rough and needs to come down.
  • The arm is good, but the glove work needs to improve at shortstop for the infield to be a plus.
  • The Cardinals gave Allen Craig, Kolten Wong, and Stephen Piscotty early extensions, and those players had put in more time than DeJong. The $26 million is the most a player with less than a year of MLB experience, according to USA Today's Bob Nightengale. Anybody who thinks this is too soon isn't out of line in thinking so.
  • We all know what happened with Diaz. He had a breakout season and then broke down. The power was gone, the shortstop work rolled faster downhill, and he was gone before you could blink in the offseason. DeJong comes up, dazzles, but will the competition adjust and make him his sophomore campaign fizzle?

Fangraphs dished on this matter on Paul DeJong's page: "Unfortunately, some of that production is stemming from pretty unsustainable numbers. 216 hitters last year had over 400 plate appearances. DeJong ranked 211th in BB/K rate (0.31) and 160th in average exit velocity (86.4). A lot of other factors, other than exit velocity, play a role in power output, but seeing mediocre exit velocity and superior slugging percentage, draws a few questions."

Essentially, they are worried about DeJong's ability to create power stats without a strong exit velocity on his hits, but then again, they are going off the limited amount of data like we are in supporting his breakout. It all depends on what stats you value and I like sustainability, which he showed in the second half of 2017.

Look, if DeJong becomes the infield version of Randal Grichuk, that's not a bad scenario at a low annual cost. If he cranks 20-25 home runs, hits around .265 and slugs .450, the contract is a win. He can play second base and third base as well, so he isn't locked into shortstop if a downward defensive spiral does occur. There are options. If he regresses, this isn't a hard contract to move.

Remember the kid has power, a great arm, and an exciting hitter profile. DeJong has the good bones of what a solid Major League player needs to look like, so there's hope that he can keep it going.

The Cardinals didn't hamper their future with this DeJong extension. What they did was lock up a fine young talent at a very reasonable rate. It may be aggressive and carry some concern, but it's hard to dispute the long-term chemistry.