Assistant director of player development Steve Noworyta said he heard reports from Venezuela last year that Martinez's pitches were sharp, but he is still pleased to hear the success has continued in the Gulf Coast.
"It's great to see him translating so well, especially in games that matter," Noworyta said.
With the bat, the most impressive Phillies draft pick in the Gulf Coast League has been first baseman William Carmona, the team's 11th-round selection out of Stony Brook. In 19 games, Carmona is hitting .371 with five doubles and three triples.
The Phillies' first-round pick, righthander Shane Watson, has yet to pitch. Noworyta said Watson threw a lot of innings this spring at Lakewood (Calif.) High, and the team doesn't want to rush him back to the mound.
"It's precautionary," Noworyta said. "You get college guys and high school guys who have thrown a lot of innings. You want to be careful with them."
Here is how the other high draft picks have done thus far:
Second-round pick Mitch Gueller has been on a short leash, pitching just 82/3 innings in three starts. He is 0-1 with a 7.27 ERA.
Outfielder Dylan Cozens, also a second-round selection, is hitting .301 with solid pop: eight doubles, one triple and two home runs.
Third-round pick Zach Green is hitting .277, but he has struggled playing third base and shortstop. Through 18 games, he has committed eight errors.
In his first week back from the disabled list, outfielder Domonic Brown batted 7 for 16 (.438) with a double and a home run for triple-A Lehigh Valley. Brown, who missed 30 games because of a right knee sprain, was hitting .266 with three homers in 47 games prior to his return.
The Phillies planned to give Brown a full season at triple-A this year, hoping to take the pressure off the prized prospect and allow him to bloom into the star that evaluators have anticipated for the last two years. The injury upset those plans, and a trade could impact the plan even more.
Brown has said that he feels most comfortable playing center field, though general manager Ruben Amaro Jr. believes Brown's future waits at a corner outfield position.
On Wednesday, leaders from the Phillies and triple-A Lehigh Valley announced the teams have extended their player-development contract through the 2016 season - the longest possible extension allowed. The two teams have been tied together since 2007, when the Phillies dropped their affiliation with Scranton/Wilkes-Barre and the IronPigs moved from Omaha to Allentown.