Scouting Hamilton, Springer in AFL

Billy Hamilton has the speed for center field, but the conversion hasn't been smooth so far. Michael Chang/Getty Images

I've seen every Arizona Fall League team at least twice so far, covering all of the hitters (batting practice and game action) and about two-thirds of the pitchers, including all of the major prospects. Here are some additional thoughts on a dozen of the top prospects based on what I've seen since last week's post.

&bull; We already knew Billy Hamilton (Cincinnati Reds) could fly -- and by that, I mean a 3.78 home-to-first time from the left side, the lowest I've ever seen on a ball put in play on a swing -- but the conversion to center field is off to a slow start, as Hamilton looks like a guy who's never played the position.

That's completely understandable, and the positive sign was a throw he made to nail a runner trying to go from first to third on a single. Hamilton never showed great arm strength at shortstop, but the throw was strong and accurate.

&bull; Kyle Gibson (Minnesota Twins) threw just 28 innings during the regular season in his return from Tommy John surgery, making him the ideal candidate to come pitch in the Arizona Fall League. (Seriously, more teams need to send their rehabbing prospects out here.) Gibson was very impressive Tuesday in his second start of the fall, working from 92-94, driving the ball down in the zone, and showing a plus slider at 83-86 that he would throw in any count, in or out of the zone, and would even back-foot to a left-handed hitter when the guy might be looking for a changeup away.

He did show a true changeup, but was mostly fastball-slider and looked like a big leaguer, and one with a higher ceiling than he showed as an amateur when he had a pretty-but-slow curveball as his primary breaking ball. I would expect him to surface in Minnesota in the second half of the season once he's built up some more arm strength.

&bull; Seth Blair (St. Louis Cardinals) had a great start to his second outing for Surprise, sitting 92-96 for the first two innings with a hard slurve at 82-85 that he was locating well to the outer half against right-handed batters. In the third inning, something went awry, whether it was fatigue or having to work from the stretch, as his velocity dropped off and his command worsened. He barely used a changeup, so between the two-pitch approach, his thin frame and the difficulty maintaining his stuff, he might be more reliever than starter.

&bull; Hak-Ju Lee (Tampa Bay Rays) has long been one of my favorite prospects for his ability to play shortstop, run and make contact, and two of those three things have been on display out here. He's a plus defender with an outstanding arm, and he can still fly, but even though the Rays have him keeping his hands back better after a midseason mechanical adjustment, he's struggled to square the ball up so far, showing difficulty picking up some better off-speed stuff and a weakness when pitchers can locate under his hands.

&bull; Andre Rienzo (Chicago White Sox) is one of a small number of Brazilian-born prospects in organized baseball. Toronto's Yan Gomes became the first Brazilian-born big leaguer when he was recalled this year. Rienzo will almost certainly double that list soon, showing multiple pitches from a slight frame that might not hold up as a starter but could be an impact arm out of the pen.

Rienzo touched 95 mph with good glove-side run on his four-seamer but relied heavily on a very deceptive 85-87 mph cutter that looked just like the fastball out of his hand. He has a true overhand curveball at 78-81 and flashed a changeup, but he preferred the cutter in ordinary changeup counts. To start, he'll probably need to work on that change, and I'd feel more comfortable if he weren't so thin (listed at 160 pounds). But he's got plenty of weapons to be a good setup man if the rotation doesn't work out.

&bull; George Springer (Houston Astros) has the same mix of very good and slightly bad I saw from him in college. He has enough tools to make him a potential All-Star, but obstacles that give him a lower overall probability than you'd like to see. He's still got great bat speed, and he's holding his hands back and out, rather than in and tight as he did at UConn. He's an above-average runner with plus raw power, something he showed with a long opposite-field homer off a right-hander in Mesa last week. The negatives are the complete absence of a two-strike approach -- Springer and Javier Baez back-to-back in the Mesa lineup is a treat if you like flailing hacks at breaking balls a foot off the plate -- and some backside collapse when he overswings, which is often.

&bull; Nick Tropeano (Astros) is pitching in relief out here after a breakout season as a starter that saw him pitching with a fastball at least two grades above what he had at Stony Brook. Tropeano was 92-94 in his second relief outing, although the pitch is flat and has very little life; his out pitch is a plus changeup at 80-82 with very good arm speed and a near-identical release point to that of his fastball, making it very tough for hitters to pick up on the pitch. His slider is fringy at best, and as a two-pitch guy, he may end up in the pen. I wouldn't bet against a changeup that good, the second-best I've seen out here after Arizona's Chase Anderson's.

&bull; I prefer to focus on prospects I like and would grade highly, but I've been asked about a number of prospects who've disappointed me so far out here. Two Washington Nationals prospects, Brian Goodwin and Matt Skole, have fallen short. Skole is an organizational player for me, a positionless slugger with a noisy, uphill swing, while Goodwin hasn't run as well or shown the same electric bat speed I saw from him in college. (Some players do look slower out here every year between fatigue from the long season and discomfort in the early-October heat.)

Matt Szczur (Chicago Cubs) has the same problematic swing I've always seen from him, way too short to generate power and so early that he can't pick up breaking balls, although he can square up a fastball for a single. ... Bobby Borchering (Astros) has been standing in the vicinity of third base, and his bat isn't going to be enough to play at first. ... Cody Asche (Philadelphia Phillies) struggled badly at third base, showing slow reactions in both directions, although I like that he's loading his hands a little deeper to drive the ball to the gaps. ... One player I'd mentioned as a disappointment in my last blog post, Dellin Betances (New York Yankees), was much better the second time I saw him, 93-95 with a better slider and something resembling average command.