Carolina League hitters spent two months unable to figure out Orioles lefty Brian Matusz. The Double-A Reading lineup didn’t have much luck either.

Matusz, 22, made his Double-A debut yesterday for Bowie and allowed just one run (it was unearned) in six innings, striking out 10 with one walk and three hits allowed. Matusz sat with his fastball in the low-90s, keeping hitters off balance by mixing his location and his pitches with a curveball, slider and changeup. It was the fourth consecutive start for Matusz without allowing an earned run, as he didn’t allow a run in his final three starts with high Class A Frederick.

The Eastern League already had Giants lefthander Madison Bumgarner. Now with Matusz also in the circuit, the EL boasts the two best lefthanded pitching prospects in baseball.

Chacin Stays Grounded

Jhoulys Chacin‘s prospect stock grew rapidly last season, as he breezed through two levels of A-ball with a nasty two-seam fastball. Now with Double-A Tulsa, the 21-year-old Venezuelan set a season-high with 10 strikeouts yesterday at Northwest Arkansas. Chacin allowed two runs, two hits and one walk in 7 1/3 innings, lowering his ERA to 3.07 on the year. Chacin is the uncommon groundball pitcher (he has a 59 percent groundball rate this year) who also strikes out batters at an above-average clip, as he has plus velocity and movement on his fastball, a good changeup and a curveball with late action.

Weeks Shows Strength

One full year after the Athletics made Miami second baseman Jemile Weeks the 12th overall pick in the 2008 draft, Weeks has spent more time off the field nursing injuries than he has spent on the field playing ball. A hip flexor injury ended Weeks’ 2008 season after signing, and he remained in extended spring training until late May because of that same injury.

Now 18 games in with high Class A Stockton, Weeks is scorching the ball, hitting .403/.494/.694 with six home runs, 11 walks and 15 strikeouts. Weeks isn’t too big–he’s listed at 5-foot-10, 175 pounds, but he has good bat speed and strong wrists, which helps him drive the ball when he connects. And because he has a solid approach at the plate, that’s been happening quite frequently so far.

Young And Powerful

With Jason Heyward out of the high Class A Myrtle Beach lineup, first baseman Freddie Freeman has been an offensive force for the Pelicans. Heyward returned to the lineup yesterday for the first time since May 26 and went 0-for-3, but Freeman was the story. While Heyward went 0-for-3 with a walk, the 19-year-old Freeman collected three hits including a double in four at-bats, one day after hitting two home runs in a game. Freeman’s outstanding June (he’s hitting .352/.410/.537 in 15 games this month) has helped lift his overall line to .310/.389/.465 with six homers, 17 walks and 32 strikeouts.