The White Sox are blowing it up, having traded Chris Sale and Adam Eaton in blockbuster deals on back-to-back days at the Winter Meetings. They are almost certainly not done, with other attractive veterans like David Robertson and Todd Frazier as trade chips, either this winter or before the summer trade deadline. But for teams looking for make a bigger splash, the White Sox have one more big trade to make, as they haven’t yet moved Jose Quintana, one of the game’s best pitchers, and a guy who is signed for four more years at bargain prices.

And for a while now, whenever anyone asked where I thought Quintana would end up, I would name the Houston Astros as the best fit. The Astros already have a very good team, but they’re a step below the best teams in baseball, and adding a frontline pitcher like Quintana seems like a way for a team with a strong young core to solidify their status as contenders both this year and for the future. Quintana’s modest salary would not prevent them from keeping any of their young stars in Houston, and since he’s around for the next four years, they could justify giving up some of the valuable young talent for which they might not have room.

The Astros have the means to get Quintana, and as a contender who could use an upgrade to keep up with Boston and the big boys in the National League, it’s not that hard to make a case for why they should push hard to land Chicago’s other ace. But the more I looked at the Astros roster, the more I began to wonder whether Houston really needs Quintana after all.

Conventional wisdom is that the Astros have a good lineup, a terrific bullpen, and a rotation that is a little bit shaky. Not coincidentally, last year, the Astros starters put up a 106 ERA-, ranking 19th in baseball, just ahead of the Phillies, Royals, and Orioles. For the most part, the current Astros rotation is the same as last year’s rotation, just with Doug Fister swapped out for Charlie Morton; not the kind of move that makes people think things are going to be wildly different this year.

But last year was last year, and even though many of the names are the same, the projections look a lot rosier for 2017.

Our depth charts, which are currently displaying the 2017 Steamer forecasts, have the Astros rotation ranked as the eighth best in baseball at this point. The ZIPS projections for the Astros are nearly identical, agreeing that Dallas Keuchel, Lance McCullers, and Collin McHugh are all above-average starters, with Mike Fiers serving as a solid enough innings-eater, and thinking Morton is not entirely useless as a fifth starter.

And, more importantly, there’s some depth here, with both ZIPS and Steamer seeing youngsters Joe Musgrove and David Paulino as something close to league-average starters next year. The Astros are unlikely to just stick both in their rotation and hope for the best, especially since Paulino has battled injuries throughout his career, but the team already has some pieces in place that could reasonably be expected to step in should Fiers or Morton struggle, or McCullers’ arm starts hurting again. There are contending teams with thin rotations, susceptible to injury or underperformance, but the Astros really aren’t one of those teams. Given what they have, they don’t really need another starting pitcher.

Now, of course, any team in baseball would be better with Quintana on it, and it’s not hard to see how Houston would be better if they used one of their young arms (with some other stuff) to land Quintana, pushing Fiers or Morton into the depth role instead. After all, he’s not just some random arm, and he’d improve the front of the Astros rotation, not the back.

Except, the Astros’ current top three are all pretty good, and it’s not super clear that bumping any of them to a potential fourth-starter role — and thus, the guy who makes just one start in a playoff series — would be an upgrade worth the acquisition cost.

For instance, here’s some data I found a bit surprising.

wOBA Allowed, 2014-2016 Name IP wOBA allowed Jose Quintana 614 0.301 Collin McHugh 543 0.307

Over the last three years, there isn’t actually all that much of a difference between Quintana and McHugh in terms of how well batters have hit off of them. Even their underlying numbers are kind of similar, with both posting similar BB%, K%, and GB% rates. Neither have been wizards at hit prevention, with both posting similarly higher-than-average BABIPs allowed. The primary difference between them is that Quintana has allowed fewer home runs, based on an 8% HR/FB ratio instead of McHugh’s 10% mark, and Quintana’s had a few more runs marked as unearned, so his ERA has been reduced more thanks to that useless classification.

Of course, compiling the last three years into one number doesn’t account for the fact that McHugh’s best season was in 2014, and he hasn’t been as good the last two years. His wOBA allowed the last two years is .323, the same as Kendall Graveman, and a little worse than R.A. Dickey. If you weight 2015 and 2016 far more heavily than 2014, then McHugh looks like the kind of guy that you don’t mind sliding into the No. 4 spot, and his presence shouldn’t be any kind of detriment to the team acquiring Quintana.

But the primary difference between 2014 Breakout McHugh and 2016 Disappointing McHugh was a .259 BABIP vs a .338 BABIP, and given his overall track record, there’s no real reason to think McHugh is going to keep giving up hits at the same rate he did last year. By the more stable indicators, McHugh was still a good pitcher in 2016, and if he gets his BABIP down even to his .312 career average, he’s a perfectly capable No. 3 starter on a contender.

So the Astros have rotation depth, and if everyone’s healthy, their top-three starters are all pretty good, so acquiring Quintana would potentially push a valuable arm into a less valuable postseason role. Quintana is certainly better than McHugh — and more reliable than Keuchel or McCullers — but the question the Astros need to ask isn’t whether it’s an upgrade, but whether the magnitude of the upgrade is worth the price the White Sox want them to pay. And, unless they aren’t convinced McCullers can make it to October healthy, I’m not sure it is. They already have rotation depth and potentially quality frontline pitching, even if the guys they are bringing back didn’t quite live up to expectations last year.

In looking at the Astros roster, the real hole appears to me to be in left field, not in the starting rotation. The team’s current plan for left field looks like a healthy dose of Nori Aoki, with Jake Marisnick and Evan Gattis also potentially getting at-bats when Aoki sits (though almost certainly, they’d play other positions, with the defensive alignment shifting around to maximize defensive abilities). None of those guys are the kinds of players you really want to count on too heavily, and with Yulieski Gurriel still a bit of a question mark at first base, it seems to me that the Astros most significant upgrade could come from landing a left fielder who could shift to first base if need be, depending on who ends up playing well enough to justify the playing time.

Replacing the Aoki/Marisnick/Gattis combination with some kind of quality everyday left fielder might be just as impactful an upgrade as adding Quintana to the rotation, and given the glut of hitters on the market, it will almost certainly be cheaper to add another bat rather than paying the price for an arm in a market where arms are in short supply. Quintana would help the Astros, certainly, but given the going rates for hitters and pitchers, they might be better off getting a left-field upgrade instead.