Jake Arrieta, RHP, Orioles (Triple-A Norfolk)

Arrieta was certainly dealing at Double-A, striking out 70 over 59 innings and limiting the Eastern League to a .208 batting average, but it was still surprising to see him bumped up to Triple-A. Not that he didn’t deserve it-he did pitch six two-hit innings in his Norfolk debut-but it’s surprising in what the move might say about his timetable. The Orioles have already looked at a lot of young arms this year at the big-league level, but they’ve stayed away from the premium guys like Chris Tillman. Now that he’s joined in Triple-A by Arrieta, one wonders if they’re simply lining up all of the pieces for a September look and a permanent installation in April 2010 as starters.

Jason Castro, C, Astros (Double-A Corpus Christi)

The Astros’ first-round pick from last last year made his own jump last week, moving up to Double-A after compiling a .309/.399/.517 line at High-A Lancaster. The hitting has continued in the Texas League, as Castro is 6-for-16 in his first four games for the Hooks. As good as his offense has been, it’s his work behind the plate that has been earning raves from scouts; he gunned down nearly 60 percent of opposing basestealers at Lancaster. Catchers with real value both offensively and defensively are rare commodities, and Castro is looking more and more as if he’ll be in the big leagues sometime next year.

Yohan Flande, LHP, Phillies (High-A Clearwater)

A 23-year-old Dominican who pitched in the Gulf Coast League last year, Flande is not a guy with a lot of hype behind him, but he’s been nothing short of outstanding this year, firing a six-hit shutout on Sunday to lower his ERA to 2.45 over 12 starts. He’s not a massive prospect, but a quick check with a scout shows that there’s definitely something there, as his fringe/average fastball plays up due to location and movement, while his changeup is truly a plus offering. He’s probably a reliever in the end, but after coming into the year without even being on anyone’s radar, that’s a massive upgrade.

Tyson Gillies, OF, Mariners (High-A High Desert)

A Canadian import who is legally deaf, Gillies is an absolute burner who the Mariners hoped would be able to take off with an assignment to the hitters’ paradise of High Desert. He’s beginning to work the count much better, and that’s helping every aspect of his game. While his two home runs on Sunday aren’t a good representation of his game, he is 12-for-19 in his last five games, batting .330/.440/.500 overall with nine triples and 16 stolen bases. We won’t know just how real this is until he gets to Double-A, but it’s definitely interesting.

Gio Gonzalez, LHP, Athletics (Triple-A Sacramento)

Gonzalez drives me nuts, and I have to wonder what effect he has on the Athletics themselves. It’s just hard to find a more inconsistent pitcher in the game today. When he’s on, he’s outstanding, and when the command falters, he’s horrible. In a three-start stretch during the middle of May, Gonzalez allowed 16 runs over 13 2/3 innings while walking 12, but since then, he’s been nearly untouchable, giving up only one run in four outings while striking out 28 and giving up just nine hits in 25 innings. It’s those kinds of performances that will get him back to the big leagues, but it’s the showings in May that also might make Oakland hesitate, as they just don’t know which version of the southpaw they’ll be getting on any given night.

Devaris Gordon, SS, Dodgers (Single-A Great Lakes)

Coming out of a slump, Gordon had six hits over the weekend including a pair of triples, and he’s now batting .289/.354/.387. That line may not be overly impressive, but at the same time it could also be the most impressive line in the league, as it’s hard to find a more raw talent on the circuit. An outstanding athlete with a body and tool set that remind some of a young Jimmy Rollins, Gordon is incredibly unrefined but still producing, and those who feel he’s just beginning to scratch the surface of his abilities also think that it’s hard to find a player in the Midwest League with as much upside.

Bryce Harper, C, College of Southern Nevada

Think Stephen Strasburg got hyped? Meet Bryce Harper, the top prospect for the 2011 draft… oh wait, make that 2010. Over the weekend it was announced that Harper, who just finished his sophomore year at a Canyon Springs High School, is done with that whole prep thing and will begin working toward his GED with the intent of enrolling in junior college next fall. That will technically make him draft-eligible next year, but there will be a hearing on the gambit sometime soon. Without question, Harper is a legitimate mega-talent, despite the aggrandized and at times apocryphal stories of his baseball prowess. Another Scott Boras soap opera is sure to follow, but more importantly, Harper’s certainly a player worth watching.

Buster Posey, C, Giants (High-A San Jose)

Posey just keeps hitting, and he’s beginning to lean toward wasting his time in the Cal League barring a promotion to Double-A. He went 5-for-10 over the weekend with a pair of doubles, and is now batting .318/.416/.534 on the season, but it’s his walk rate that might impress at first look, though it could also become a concern for his development. In 13 games this month, Posey has 39 at-bats and 13 walks, and it’s not because he’s suddenly turned into Wade Boggs, but because everyone is pitching around him in a weakened San Jose lineup. He needs the challenge of a higher level, where opposing teams will focus on getting him out.

Anthony Rizzo, 1B, Red Sox (Single-A Greenville)

Rizzo’s recovery from cancer continues to be not only inspiring, but also impressive; he had two hits in each of his three weekend games, including his ninth home run on Sunday, and is now batting .340 in June and .286/.357/.476 overall. First-base prospects are difficult to evaluate, and one needs to be a true offensive force to profile well as a prospect, and though Rizzo isn’t quite there yet, he is quite possibly on his way. He can certainly hit, but his attributes in the power and patience departments are merely average. Still, he’s just 19, there’s plenty of time, and you really do have to root for him.

Alex White, RHP, University of North Carolina

After saving his draft status with an outstanding start in the super regionals, White maintained the roll he’s been on in the College World Series over the weekend, firing nine fantastic innings against a very good Arizona State team while allowing one run on seven hits and striking out 12. The 131 pitches may have drawn a few winces from Indians‘ officials in attendance, but maybe they took comfort in the fact that they plan to convert their first-round selection to a reliever, which, based on his arm action and repertoire, is arguably his most logical role. If he signs quickly, he could be a favorite to be the first non-Strasburg draftee to reach the big leagues.