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Carlos Correa, SS
The list of Astros' spring training invitees is far more impressive than the MLB team that will take the field on Opening Day.
Carlos Correa is the best of the bunch, even though he won't reach the big leagues until 2015, at the earliest. He was the No. 1 overall pick in the 2012 draft, ahead of Byron Buxton and Mark Appel.
Lauded for his hitting ability coming out of the Puerto Rico Baseball Academy, Correa dazzled in his first full season of professional ball, posting a .320/.405/.467 slash line as one of the youngest players (18 on Opening Day) in the pitcher-friendly Midwest League.
Jim Callis of MLB.com recently wrote that some scouts are comparing Correa favorably to the likes of Alex Rodriguez, Troy Tulowitzki and Manny Machado.
If that doesn't get you excited, Houston, nothing will.
George Springer, OF
There are few prospects in baseball who can match Springer's value relative to position. He's an excellent defensive center fielder, with range for days and plus arm strength, and brings elite power potential with the ability to steal bases, as well.
His biggest flaws are a long swing and poor two-strike approach that lead to high strikeout totals, but even with those problems, Springer's average, on-base and slugging percentages and home run totals have gone up every year in the minors.
Scouting stat lines is always a fool's errand, and Springer isn't likely to be a .300 hitter in the big leagues with 150-160 strikeouts, but his ability to work deep counts and draw walks makes him a candidate to post high OBP totals with enough contact to hit 20-25 homers.
Springer tore up Double-A and Triple-A last season (37 homers, 1.010 OPS), so it shouldn't take long for him to arrive in Houston this year.
Mike Foltynewicz, RHP
Mark Appel gets all the hype among Astros' pitching prospects because he was the No. 1 overall pick last year, but Mike Foltynewicz is the most exciting arm in the system.
A strong 6'4", 200-pound right-hander, Foltynewicz can throw a fastball 100 mph like it's nothing. His kind of arm strength is rare to find, though there are holes that have to corrected for the 22-year-old to reach his full potential.
The secondary stuff is just OK at best right now. Foltynewicz throws a curveball and changeup, but the breaking ball lacks consistent shape and the change is thrown too hard with little command to fool anyone.
Commanding the fastball and seeing even a half-grade jump in the curveball and changeup will make Foltynewicz at worst a mid-rotation starter with the potential for more because the heater is so good.
Mark Appel, RHP
Admittedly I only saw Mark Appel in person once last season late in the year after he went through the entire college season and draft process, but he left me cold.
There's plenty to be excited about. Right-handers don't often come along with above-average command, easy mechanics that they repeat well and flash three above-average or better pitches right out of the gate.
But Appel wasn't missing any bats at Low-A, a level he's far too advanced to struggle in. It was just one game, so don't read too much into it.
Appel still has all the ingredients of a solid No. 2 starter. I look forward to seeing how he looks after an offseason to recover, as well as how aggressively the Astros push him this spring after an emergency appendectomy on January 30.