ACES IN WAITING?

ACES IN WAITING?

The Nationals have no shortage of promising pitching prospects in their farm system. History says most of these guys won’t pan out, but here’s a look at those young arms who have a chance to one day be staff ace:

COLLIN BALESTER

Throws: R | Ht/Wt: 6-5, 190 | Age: 21

Acquired: Fourth-round pick in 2004 draft

Last year: 4-10, 3.89 ERA at Harrisburg and Columbus

The lowdown: With a complete arsenal that includes a mid-90s fastball and a hard curveball, Balester has moved quickly through the Nats’ system. He impressed team officials this spring and could be the first starter promoted from Columbus.

ROSS DETWILER

Throws: L | Ht/Wt: 6-5, 185 | Age: 22

Acquired: First-round pick in 2007 draft

Last year: 2-2, 3.51 ERA at GCL and Potomac

The lowdown: Probably has the best pure stuff of anyone in the system, including a “plus” fastball, curveball and change-up. Has only nine games of minor-league experience, but he’s on the fast track to the big leagues.

JACK MCGEARY

Throws: L | Ht/Wt: 6-3, 195 | Age: 19

Acquired: Sixth-round pick in 2007 draft

Last year: 0-1, 13.50 ERA at Vermont

The lowdown: A very polished lefty, McGeary might have been the steal of last year’s draft. The Nats convinced him to sign by offering to let him attend Stanford while still pitching during the summer.

GARRETT MOCK

Throws: R | Ht/Wt: 6-4, 215 | Age: 24

Acquired: Traded with Matt Chico from Arizona for Livan Hernandez

Last year: 2-7, 5.12 ERA at GCL, Potomac and Harrisburg

The lowdown: A big, flame-throwing Texan in the Roger Clemens/Nolan Ryan mold, Mock is finally over a knee injury and flashed some of his talent this spring in big-league camp. Along with Balester, he’s closest to major-league ready.

JOSH SMOKER

Throws: L | Ht/Wt: 6-2, 195 | Age: 19

Acquired: Supplemental-round pick in 2007 draft

Last year: 0-0, 4.50 ERA at Vermont

The lowdown: The second of three top lefties drafted by the Nats last summer, Smoker has some raw talent but still needs to harness it. Known for a fastball-curveball combo, he’ll start the long trek to the majors this year.

COLTON WILLEMS

Throws: R | Ht/Wt: 6-3, 175 | Age: 19

Acquired: First-round pick in 2006 draft

Last year: 3-2, 1.84 ERA at Vermont

The lowdown: One of the studs of last summer’s dynamite Vermont rotation, Willems has loads of potential. But he still needs to refine his secondary pitches to keep himself out of bad counts.

JORDAN ZIMMERMANN

Throws: R | Ht/Wt: 6-2, 200 | Age: 21

Acquired: Second-round pick in 2007 draft

Last year: 5-2, 2.38 ERA at Vermont

The lowdown: Lost among all the lefties the Nats drafted last summer, Zimmermann could make it to the majors faster than any of his classmates. A tough battler who pitched with a broken jaw in college, he’s well-thought of in the organization.

— Mark Zuckerman