The Houston Astros have reportedly signed AL MVP and star second baseman Jose Altuve to a five-year, $151 million contract extension. This is of course huge news for the 'Stros and their partisans, as it means one of the most beloved players in franchise history is now secured until his mid-thirties. 

The matter of Altuve's extension will of course raise the matter of his double-play partner, shortstop Carlos Correa, and his long-term future in Houston. Locking up Correa long-term, however, will be much more difficult and much more costly than inking Altuve was. Here's why that's the case ... 

Correa is an excellent player who may not have reached his ceiling

Altuve is of course also an excellent player, but we may just be getting a glimpse of what Correa can do. He enters the 2018 season with a career batting line of .288/.366/.498 (138 OPS+) and an average of 30 home runs per 162 games played. Last season, Correa was limited to 109 games played because of a torn thumb ligament, but he authored a line of .315/.391/.550 (158 OPS+) as a 22-year-old.

Players these day are peaking earlier than they once did, but Correa still may have room to improve. Last season, though, he proved he's capable of hitting like an All-Star first baseman while also being a defensive asset at the premium position of shortstop. To become all of that at age 22 is rare indeed.

Framed another way, a player who provides such immense value relative to his positional peers isn't likely to sell away his free agent years at anything less than a premium. 

Correa is on target to be a very young free agent

Speaking of Correa's free-agent years, he enters the 2018 season with two years and 119 days of MLB service time. That puts him on course to become a free agent at the end of the 2021 season. He'll be just 27, thanks to Correa making his big-league debut at the age of 20 years, 259 days.

Barring unexpected decline or career-altering injury, Correa's going to hit the market as one of the very best players in baseball with peak or near-peak years remaining. Next winter, Bryce Harper will almost certainly sign the largest contract in baseball history. If Correa maintains his current trajectory or even plateaus at 2017 levels while hitting the market on schedule, then he'll break Harper's presumptive record. So, yeah, it's going to cost a lot to buy Correa out of that possibility. 

Correa already has financial security (and thus isn't desperate)

Players who haven't yet secured life-changing money tend to be more open to signing long-term extensions. In Correa's case, he's not especially desperate. As the top overall pick of the 2012 draft, he received a $4.8 million signing bonus. He's already made roughly $1 million in MLB salary, and this season he's under contract for another $1 million. To boot, Correa is eligible for arbitration next offseason, which is going to mean a substantial jump in salary even if he has a down year.

Throw in lucrative endorsements with companies like Adidas and Topps, and Correa's better off than, say, most international amateur signees, whose market is even more artificially restricted.  

Time may be running out

Early in the 2017 season, Correa's agent said his client would never sign an early contract extension. Soon thereafter, Correa walked those comments back a bit, but only a bit. Via MLB.com's Brian McTaggart ... 

"I've still got five more years of being here, so if the Astros come to me and they want to negotiate and the price is right, we'll consider it," Correa said. "Right now, I'm in the stage of my career where I'm just going to play baseball and try to put up numbers. They try to do something, it's got to be early. ... I've got to focus on playing good baseball so I can have good arbitration years."

By "early," Correa means that once the 2018-19 offseason begins and he's eligible for arbitration, an extension is off the board. Minds can change, of course, but that's a perfectly rational stance for Correa.

Also, Correa may be talking about an extension that runs just through those arbitration years and not into his free agency, which isn't all that uncommon mostly because it provides the team with some degree of payroll certainty. In other words, signing an extension that eats into free agency may not be something Correa would even consider.

Split the middle between his agent's comments and Correa's diplomacy, and it's still a "price is right" matter, to quote Correa's own words. In other words, it would cost the Astros a lot -- way more than they guaranteed to Altuve. 

For all those reasons, Astros fans should savor Altuve and Correa while they have them together. All signs point to Correa's breaking up the band in another four years -- unless, of course, the Astros want to make an offer that redefines the contract extension as we know it.