Myrtle Beach's Robbie Erlin and Kinston's Drew Pomeranz have been the most effective pitching prospects thus far in the high Class A Carolina League—though the two lefthanders offer a contrast in body types and pitching styles. The 6-foot Erlin, who won the ERA and strikeout-to-walk ratio titles in the low Class A South Atlantic League a year ago, has provided terrific value as a Rangers third-round pick in 2009. The physical, 6-foot-5 Pomeranz went to the Indians with the fifth pick in last year's draft, and the 22-year-old's power repertoire is evident in his CL-leading rate of 13.5 strikeouts per nine innings.

The 20-year-old Erlin combines fluid mechanics, three quality pitches and feel for his craft to work deep into games, as he did yesterday in completing seven shutout innings in a 2-0 win against Potomac. He allowed just two hits while striking out 10 and walking none. Erlin saved his best stuff for the heart of the Nationals' order, fanning their 3-4-5 hitters multiple times each. That works out to two whiffs by right fielder Destin Hood, three by first baseman Steven Souza and two by third baseman Stephen King. Erlin retired the final 12 batters he faced and struck out Hood (looking), Souza (looking) and King (swinging) to end his seventh and final frame.

No CL pitcher can top Erlin's 22 innings on the season—or his 0.68 WHIP—and only Pomeranz has more than his 26 strikeouts.

Pomeranz had to leave his start early on Monday with a tight hamstring. He told the Kinston Free Press that the hamstring responded well to treatment and he doesn't expect to miss his next start.

• The Orioles selected Auburn center fielder Trent Mummey in the fourth round of last year's draft, and the 22-year-old needed only about two weeks this season to earn a promotion to high Class A Frederick. In 14 games with low Class A Delmarva he batted .291/.377/.509 (16-for-55) with 10 walks, 11 strikeouts and a 12-for-14 showing stealing bases. Add in two doubles, two triples and two homers and you have a picture of his well-rounded game. For his Carolina League debut, the lefty-swinging Mummey doubled, tripled and singled twice to fall a home run short of the cycle in his six at-bats. He drove in five runs while scoring two.

• The Orioles highlight reel doesn't end with Mummey's big night. Low Class A Delmarva shortstop Manny Machado connected for his first home run of the season, and second of his young pro career, as part of a 2-for-4 night. His three-run blast put an exclamation point on a five-run second inning in the Shorebirds' 7-3 win against Savannah. The 18-year-old Machado is batting .290/.392/.468 (18-for-62) through 62 at-bats.

• Mets third baseman Aderlin Rodriguez, making his full-season debut for low Class A Savannah, homered in his second consecutive game to continue his recent hot spell after an early funk. The 19-year-old began the year in a 3-for-36 (.086) tailspin, but since April 18 he's gone 9-for-30 (.300) with three doubles and two homers.

• Padres first baseman Anthony Rizzo reclaimed sole possession of the Pacific Coast League lead for home runs by smacking his seventh yesterday, part of a 3-for-5 day. He also leads the loop with 26 RBIs and is batting .432/.494/.797 through 74 at-bats.

• The Triple-A International League's youngest arm, Braves righty Julio Teheran doesn't let his youth or relative inexperience show. The 20-year-old completed eight innings for Gwinnett in a 4-3 win against Charlotte. Teheran struck out seven and walked one, while allowing three runs on six hits—though he has yet to surrender a home run through 24 innings.

• Triple-A Albuquerque center fielder Trayvon Robinson worked his way on base twice in five trips to the plate yesterday in a 7-6 Isotopes win against New Orleans. The 23-year-old Dodgers prospect singled and walked (intentionally) and now has collected a hit in 12 straight Pacific Coast League contests. Robinson's streak is actually more impressive than that, as he's hit safely in 14 of 16 games for Albuquerque and worked walks in the other two, so his on-base streak covers the entire season. He's batting .350/.426/.633 through 60 at-bats with four homers, a double and two triples on the year.

• Low Class A South Bend lefty David Holmberg (Diamondbacks) struck out a career-high 12 batters in seven innings of work. He allowed two runs (both unearned) on four hits and took the loss because his Silver Hawks teammates scored only one run.

• The main knock on Braves righthander Arodys Vizcaino is that he has yet to prove he can stay healthy for a full season. That criticism is flaring up again here in 2011, as Vizcaino is battling back problems again. He was pulled from his start on Monday night in the fourth inning after he felt a back spasm. According to the Lynchburg News-Advance, Vizcaino was already struggling before the back injury.

"He’s going soft too much," Lynchburg pitching coach Derek Botelho told the News-Advance. "He’s not going out there and establishing his fastball right now. His back wasn’t bothering him in the first and second inning. He’s got to pick it up a notch, to me. He’s got to establish his fastball off the bat. He’s not a guy that throws 88-89. He throws 94, 95 mph. I think in the future when he’s out there, and we talked about it when he was taken out, that he’s pitching a little passive, and he needs to pick it up and pitch aggressively and establish his fastball. Then the other two pitches (changeup, curveball) will work off of that. Hitters right now are taking too good of hacks off of him."