Javier Baez, SS, Cubs (Low-A Peoria)
Baez was at it again over the weekend, going 7-for-12 with a double, two triples and a home run, lifting his season line to .331/.394/.586 since joining the Chiefs in late May. Expected to be awfully good, Baez has actually exceeded those expectations, earning 70 or higher scouting grades for both his hit and power tools. He's eclipsed Minnesota's Miguel Sano in the eyes of most as the top all-around offensive prospect in the Midwest League, and he's one of the top offensive prospects in any league.
Joey Gallo, 3B, Rangers (Rookie-level AZL Athletics)
A supplemental first-round pick who arguably had more raw power than any player available, Gallo has certainly proved he can hit balls a long way; with two more home runs over the weekend and six in his last eight, he leads the Arizona League with 11 in just 63 at-bats as part of a total line that sits at .349/.528/.952. What does this all mean? Well, it means about as much as No. 1 overall pick Carlos Correa's .169/.217/.277 line in 65 Gulf Coast League at-bats. These are complex leagues, and statistics mean nothing. Go look at what Chipper Jones and Derek Jeter did at this level, or Andrew D'alessio or Joseph Winkler. This is not to crush any dreams on Gallo, who has been nothing short of amazing, but his stock doesn't suddenly move after 20 games. He still has fantastic raw power, he still has a lot of swing and miss in his game, and he still has a long way to go defensively. He's very good, but three weeks doesn't make anyone great.
Billy Hamilton, SS, Reds (Double-A Pensacola)
Hamilton moved up to Double-A this week, and while he went just 2-for-9 over the weekend, he's still providing plenty of excitement. He's stolen five bases in his five games for the Blue Wahoos (I swear, that's what they call themselves), and on Sunday afternoon he delivered an inside-the-park home run that Larry Granillo timed at a record-breaking 13.8 seconds. Along with Hamilton's off-the-charts speed, scouts, while still leaning towards wanting him to move to center field, have noted defensive improvements at shortstop, and either way, it's looking more likely than ever that he'll get to the big leagues at some point in 2013.
Alfredo Marte, OF, Diamondbacks (Double-A Mobile)
Marte was one of those players a lot of people wanted to get their eyes on at last Sunday's Futures Game. Most of the players were well known, with long-held reputations, but Marte came out of nowhere. Entering the year with little, if any, fanfare, Marte just keeps on hitting, as after going 6-for-13 over the weekend with his 16th and 17th home runs, he's now batting .303/.375/.602 in 71 games. Just six feet tall and well over his listed weight of 190 pounds, Marte is a squarely built slugger who is a bit too aggressive at the plate, but takes a huge swing while also showing a decent feel for hitting; while he's a below-average runner, he's a decent outfielder with enough arm for right. His ability to absolutely clobber left-handed pitching should lead to some kind of big league career, but he has some believers out there as a future everyday player.
Cody Martin, RHP, Braves (High-A Lynchburg)
Martin arguably had the best start of the weekend, striking out 14 during a two-hit shutout against Salem. And he's been good all year, as he now has a 2.80 ERA for the Hillcats with 101 strikeouts in 86.2 innings. Studly numbers to be sure, but Martin is not a top prospect. He sits at 87-91 mph with his fastball, and his changeup and curve are merely average. He succeeds on outstanding command and control, and when everything is on—as it was on Friday—he can be what one scout calls “surgical.” He's not a prospect getting a lot of attention, and he just doesn't have the stuff to be a impact big leaguer, but there's some value here.
Brandon Nimmo, OF, Mets (Short-season Brooklyn)
Nimmo was hitting just .188 heading into the weekend, with only three multi-hit games in 23 contests, but he reeled off three in a row, going 7-for-11 to raise his season line to .242/.391/.385. Scouts don't know what to make of him, other than really liking him. For such a raw player, he consistently puts together quality at-bats, but for every scout that thinks he's going to turn into a power hitter, you can find one who think he's going to be more of a high-average gap-to-gap type. The good news is nobody seems to think he's going to be bad, and we have plenty of time to figure out what kind of good player he has the potential to be.
Gregory Polanco, OF, Pirates (Low-A West Virginia)
At the beginning of the year, the Pirates' Sally League affiliate was all about big-money 2011 draftee Josh Bell, but with Bell injured, shortstop Allen Hanson and Polanco have become two of the biggest stock risers in all of the minors. With five more hits over the weekend, Polanco is hitting .449 (22-for-49) in 13 July games, and at .318/.380/.515 on the season, he's been getting it done all year. At six-foot-four, the 20-year-old Dominican looks plenty good in a uniform, with a long-limbed, projectable frame, and he's already showing plus speed, the potential for plus power, a good approach and good center field defense. Don't look now, but the Pirates suddenly have some position prospects to go with their high-ceiling pitching. Whether they are future Pirates or future trade chips is still to be determined.
Domingo Santana, OF, Astros (High-A Lancaster)
While 2011 first-round pick George Springer and his .331/.408/.576 line seem to get all the attention in Lancaster, not all scouts are convinced he's a better prospect than Santana. With a 6-for-11 weekend that included two doubles and two home runs, Santana is hitting .313/.383/.556 to nearly match Springer, and here's the kicker: he's almost three full years younger, and doesn't turn 20 until August. He doesn't have Springer's all-around tools, and has the same kind of contact issues, but he also has a classic right-field profile, as well as home/road splits that aren't nearly as jarring. When ranking the two, it's much closer than it seems at first glance.
Dan Straily, RHP, Athletics (Triple-A Sacramento)
Straily crossed the fluky barrier a long time ago, and now he has crossed from very real prospect to one of the better right-handed pitching prospects in the game. On Friday, Straily had arguably his best start of the year, whiffing 13 over seven one-hit innings, and your minor-league leader in strikeouts now has 154 in just 118.1 innings while allowing just 85 hits and 34 walks. Straily attacks the strike zone with three plus pitches:a 90-93 mph fastball that can touch 95, and a slider and changeup combination that can keep both left-handed and right-handed hitters off balance. It might sound weird, but the A's are in a playoff race, and Straily could get a shot at helping their cause this year.
Zack Wheeler, RHP, Mets (Double-A Binghamton)
Wheeler tossed his first complete-game shutout as a pro on Saturday, lowering his ERA to 2.39 during the six-hitter, which led to plenty of calls to get him to the big leagues, even though Matt Harvey is more primed to help the club and will likely get first dibs on a roster spot. But that's not what this is about. With just over two weeks to go until the trading deadline, Wheeler's name is coming up a lot in talks with teams. Not in the sense that he's available (he's not), but more for what he represents. Last year, when the Mets put outfielder Carlos Beltran on the market, they eschewed the package deal, instead focusing on what deal would provide them with the single best prospect. That turned out to be Wheeler, and as of right now, that deal is looking awfully good for the Mets. That has some of this year's sellers thinking in a similar vein, forgetting about combinations of players and focusing on the one best prospect they can acquire. It will be something worth looking for as the swaps start to happen.