Francis Martes didn't blow a whole lot of hitters away on Friday night, but he was tough to figure out.
"Not even any of the outs were really hit hard," Double-A Corpus Christi pitching coach Dave Borkowski said. "He didn't have anyone reach second base. You've got to respect the fastball, and when he's able to throw the off-speed pitches for strikes, he really keeps the hitters off-balance."
The Astros' No. 2 prospect allowed three hits and a walk while striking out four over seven innings as Corpus Christi zipped visiting Midland, 7-0.
Martes (9-5) has a 3.32 ERA in 24 Texas League games, including 21 starts, with 126 strikeouts over 122 innings. Friday's outing was his first scoreless one since he twirled seven one-hit innings on July 27 at San Antonio.
"I would say in this start he was not as sharp as he was in the one in July, especially with his fastball command. He was a little elevated, a little divey, especially working in the stretch," Borkowski said. "His slider and his changeup worked very well tonight. This might have been his best night for the changeup, maybe because he didn't have his fastball command. He threw it ahead, behind, at any point in the count. He got a lot of weak outs on that."
The 20-year-old right-hander rolled through five innings having given up one hit, a two-out single in the second by Tyler Marincov.
"I think he was on point [from the beginning]," said Borkowski, a former big leaguer. "He warmed up well and he was ready to go. We've had a good stretch going with our starters. I think they're all feeding off each other, and he wanted to keep that going and feed off it."
Martes issued his lone walk leading off the fifth, and his pitching coach was glad to see MLB.com's No. 34 overall prospect buckle down and retire the next three Rockhounds in order.
"It's a growing-up process. Now, he gets it," Borkowski said. "In the past, that could have snowballed into two or three walks in the inning. It's no big deal for him now. He brushes it off and stays under control. He leaves the runners out there instead of turning it into what could easily snowball into three runs in the inning."
After working around a two-out infield hit by A's top prospect Franklin Barreto in the sixth and a one-out base knock by Andy Paz in the seventh, Martes had thrown 59 of 92 pitches for strikes.
"He wants to keep going every time. He's a bulldog, a gamer," Borkowski said. "He doesn't run out of gas and he's always asking us for more innings. Now, he did his job and that's where we have to step in and be the voice of reason."
Eric Peterson took over for Martes, striking out four over two perfect innings.
Astros No. 14 prospect J.D. Davis homered for a second consecutive game, doubled and drove in two runs. Drew Ferguson was 3-for-4 with a two-run homer in his sixth Double-A game.
Midland starter Brandon Mann (2-3) allowed two runs on four hits and two walks with eight strikeouts over six frames.
Josh Jackson is a contributor to MiLB.com. Follow and interact with him on Twitter, @JoshJacksonMiLB.