High-Class A Potomac shortstop Jason Martinson, the player who kept No. 11 while Ryan Zimmerman wore No. 33 in his rehab appearance Wednesday in Woodbridge, has been impressive as he bears down on reaching Class AA.

Martinson, a 24-year-old former Texas State wide receiver, won two Carolina League player of the week honors in April. He is tied for fourth in the league with five home runs and tied for fifth with 17 RBI while hitting .272 with a .389 on-base percentage and .522 slugging percentage.

“I’ve been seeing the ball well and keeping my approach simple, trying to execute in certain situations,” Martinson said. “I’m just trying to be more consistent.”

A year ago, Martinson had 106 RBI and 104 runs in 135 games between low-Class A Hagerstown and Potomac.

“His numbers stand out to you, but I’m really happy with the improvements he’s made defensively,” said P-Nats Manager Brian Daubach, who also had Martinson on his team at Hagerstown in 2011 and for 69 games in 2012. “He’s really attacking the ball now. He has the arm strength. He’s such a good athlete, I just think he needs to play more games at the position.

“Being a football player, he didn’t play as many games as some other guys, but the quickness has always been there because he’s been a good base stealer throughout his career.”

The 6-foot-1 Martinson is 64 for 79 on career stolen base attempts. He played some third base at Potomac last season and then in the Arizona Fall League, but Daubach said Martinson’s reads at short are better than ever.

“In our last road series at Myrtle Beach, he made two plays that I haven’t seen him make in the past couple years,”  Daubach said after Tuesday night’s doubleheader sweep of the Carolina Mudcats.

Both plays were up the middle, and one was on a dive. Martinson has played shortstop in 16 games (with two errors) and been the DH in the other 10.

“I’m always working on every aspect of the game — defensive and offensive — and I’ve been working with the coaches on both sides, and it’s paying off well so far,” Martinson said.

RAY ENJOYS A TURNAROUND: While Martinson carries over success from 2012 in the Carolina League, 21-year-old left-hander Robbie Ray is doing his part to recover from a seemingly lost season.

Ray, who signed for a $799,000 bonus as a 12th-round pick in 2010, is 2-1 with a 1.24 ERA in 29 innings after going 4-12, 6.56 in 105 2/3 innings in the same league last year after spending time at extended spring training. Eventually, his work with Potomac pitching coach Chris Michalak and Nationals minor league pitching coordinator Spin Williams took hold.

“Robbie worked hard over the winter, and you can tell,” Daubach said. “He’s physically stronger and he came into spring training with a really good attitude. He threw well in spring training, and it’s really carried over.

“He’s a competitor and he wanted to prove that last year was a fluke, and he’s on his way to doing that.”