I don't disagree with Brad's view that it's time for Jacob Lindgren to enjoy the culture clash of life in NYC. (Side note: I wish on-the-ground reporters would report more about what it's like for a Mississippi native, who then attended Mississippi boarding school and Mississippi State, to move to NYC at age 22. My NY-CA move was jarring at 18, and my NY-WI move was jarring at 30, but I can only imagine what it'll be like for Lindgren….) But while I'm in favor of the callup, I'm pessimistic that he'll succeed from the get-go. Here's the big red-flag question: How will his unimproved control will play (a) in the bigs and (a) in repeat viewings? In just 46.2 minor-league innings, 4.4 BB/9, with no real improvement in AAA this year (4.1 BB/9). Big-league hitters will be all the more able to lay off the out-of-zone stuff, not only because they're better, but also because they'll see him repeatedly -- unlike his minor-league opponents. Thanks to his meteoric rise, Lindgren logged only 5-22 IP in each league, so he never experienced opponents learning to lay off this or that pitch the next time they see him; after the first time the Mudville Muddies saw him mow them down yet miss the plate a lot, they couldn't learn from the experience next time, because he was gone from the league. The second or third time he faces Baltimore or Toronto could be a rude awakening.
But Lindgren's best shot of learning he needs better control is, frankly, moving to the Bronx, where he not only will get better pitching coaching, but, just as importantly, will get him smacked around by big-leaguers who lay off the wild stuff. If I'm Lindgren and I'm racking mowing down AAA competition to the tune of a 1.20 ERA, 0 HR, and 11.9K/9 , I roll my eyes when the Scranton pitching coach tells me I really really need to improve my control, because I already feel like I'm the best. Even if he hadn't taken that attitude, he'll experience a whole different motivation to improve his control when he starts having to throw more hitter's-count fastballs to big-leaguers with the plate discipline to take him to 2-0, 3-1, etc. I mean, wild pitchers tend to have high HR rates not only because they accidentally throw it miss in the middle, but also because they get into hitter's counts that too often let hitters correctly guess "best-high fastball."
Even if it's better for Lindgren's development to be in the bigs, can the Yankees tolerate his growing pains? If you think the 2015 Yankees are hopeless (not my view, but it's a reasonable one), then sure, rebuild by maxing the playing time of Slade Heathcott, Rob Refsnyder, Jose Pirela, and Lindgren, at the expense of past-prime 30somethings like Carlos Beltran, Stephen Drew, Brendan Ryan if he's ever healthy, and Esmil Rogers. But even if the Yankees aren't hopeless, it's not that damaging to break in a risky reliever. I've been on the "Dump Rogers" bandwagon for a while, but another plus is that his "eat innings when up or down 6-10 runs" role could be a safe place to break in Lindgren.
And while Lindgren's control is a flaw, all humans are flawed -- especially pitching prospects. None come to the majors with a perfect no-holes-in-game profile -- and when they do, don't trust it. The Yankees' last no-holes pitching prospect I remember was Phil Hughes, and it turned out his homer-proneness didn't show until he faced big-league hitting. Many pitchers aren't finished products through years 2, 3, or 4 in the bigs -- like we've seen with Michael Pineda, who took years to master a useful changeup, and Nathan Eovaldi, who's kid of still working on making the changeup or curve a useful third pitch that lets him avoid seeing (to give an actual example) his 5th consecutive straight high-90s four-seamer get crushed by the decayed 2015 version of Curtis Granderson.
So, is Lindgren truly ready to be a quality big-league reliever? Probably not. Is he a risk? Absolutely. But is it time to give him a shot? Absolutely, because the learning needs is in the bigs, and he's earned his shot by showing he has a huge upside and nothing left to prove in the minors.