A sampling of this week's prospect updates:

Natonal League

12 Brett Jackson CHC OF B+ Has turned it on in August - .369 with 5 HR. 29 K in 20 games however.

15 Jonathan Singleton HOU 1B B+ HR every 20.8 AB vs 35.6 in Phillies organization. Factor in a .380 OBP and he's done well.

19 Billy Hamilton CIN SS B+ Back-to-back four-hit games and up to 91 SB. This generation's Vince Coleman.

20 Yasmani Grandal CIN C B+ .293/.388/.494 overall and .357 avg in last 10 games. Should be ready sometime in 2012.

23 Jose Altuve HOU 2B B+ .322 in first 115 big league at-bats, so should lose eligibility for this list by next week.

2 Julio Teheran ATL SP A Back-to-back solid starts after a brief rough patch. Remember, he's still just 20.

3 Shelby Miller STL SP A Suspended and reinstated following alcohol-related incident. Don't blow this out of proportion just yet.

4 Jameson Taillon PIT SP A 4.52 ERA isn't great, but 80:17 K:BB in 79.2 innings for a kid his age is quite good.

14 Alex White COL SP B+ 5 ER in 6 IP in first start since 7/23, but showd good velocity and should be fine.

16 Zack Wheeler NYM SP B+ 2.70 ERA in four starts since joining Mets organization. Great great trade for them.

American League

31 Nick Castellanos DET 3B B .342 in August but no HR. 6 HR for the year and .310/.363/.433 overall.

32 Grant Green OAK OF B Has cooled off a little but still .397 in August. Surprised to see EYE as low as 0.36 however.

33 Nick Franklin SEA SS B Gets bump to AA where he starts by hitting .500 with 3 SB in first 32 at-bats.

34 Aaron Hicks MIN OF B 71 BB and 15 SB but contact (.232 avg) and power (5 HR) just isn't there yet.

37 Gary Sanchez NYY C B As of Tues, .433 avg and 7 HR in last 9 games but hasn't played since 8/11.

24 Taijuan Walker SEA SP B+ Last 3 GS: 15 IP, 1 ER, 16:7 K:BB but hasn't pitched since August 10.

26 Mike Montgomery KC SP B+ Hasn't been horrible lately, just not as good as the scounting reports.

41 Zach Stewart CHW SP B Will re-join rotation with news that Humber requires a DL stint.

42 Sonny Gray OAK SP B 8.1 IP, 1 ER, and an 8:2 K:BB in pro debut. 2011 first-round pick.

45 Drew Smyly DET SP B 0.93 ERA in 5 AA starts and a 113:34 K:BB in 109.1 innings overall.