HOUSTON -- The Pirates' 10-game homestand didn't distract Neil Walker from picking up right where he left off.

Walker went 2-for-4 in Tuesday's series opener against the Astros, and has hit safely in each of his last 10 road games, going 15-for-41 with nine RBIs in that span.

"We feel like soon ... the pitching will continue to keep doing what it's doing, and our offense is going to match that," Walker said. "When that happens, you're looking at some blowouts."

Walker has hit safely in 17 of his last 18 road games since May 2. His second-inning run on Tuesday night gave the Pirates and Jeff Karstens all they needed to secure a victory.

"I just wanted to get on base and see what would happen, and fortunately I ended up on second with nobody out," Walker said, "and Garrett Jones got himself in a 3-0 count and put the ball in play. It's nice to get those hits to start things off."

Beimel has trouble throwing off mound

HOUSTON -- Joe Beimel had no problems throwing off flat ground, but couldn't say the same after throwing off the mound on Tuesday.

Beimel, who last pitched on May 27 and is on the 15-day disabled list with left elbow inflammation, said he threw 20 pitches without pain -- but after the 10th pitch, it felt like "he was throwing balls with parachutes on them."

"As I kept throwing, it got weaker and weaker," Beimel said. "It's just kind of weird. I felt good throwing off flat ground, and as soon as I got on the mound, the first 10 were really good -- and the second 10, the ball was barely getting there."

He said will continue to work on strengthening his elbow before returning to the mound at the end of the road trip or immediately after the Pirates return home. He threw off flat ground again on Wednesday, and said his elbow felt fine.

"It's just so weird from one day to the next," Beimel said. "It felt outstanding today, and the ball was carrying really well."

The news was more upbeat for infielder Josh Harrison, who hit on Wednesday morning for the first time since injuring his right oblique.

"He did everything today, and actually pulled it off very, very well," said manager Clint Hurdle. "I'm going to try and stay away from him tonight, and if he feels good tomorrow, I think we can get him back in play."

Diaz gets call in two-hole vs. Happ

HOUSTON -- The No. 2 spot in the lineup for the middle game of the Astros series was once again filled by a Pirate with a successful track record against Houston's starting pitcher.

Matt Diaz, who is 7-for-12 with a home run, a double and just one strikeout against Astros starter J.A. Happ, started in right field and batted second on Wednesday.

Manager Clint Hurdle slotted Ronny Cedeno in the two-hole on Tuesday. The shortstop was 5-for-9 against Tuesday's starter, Bud Norris, entering that game.

Happ, a southpaw, has surprisingly allowed a .333 batting average to left-handed hitters and just a .232 average against right-handed hitters this year. Still, lefties Garrett Jones and Xavier Paul are out of the lineup on Wednesday. Jones is 1-for-12 in his career against Happ.

"I can play Paul over [Jose] Tabata, and Jones over Diaz," said Hurdle. "Not going to do it [on Wednesday]. I like this lineup I'm throwing out."

Hurdle said there are times he'd consider stacking his lineup with lefty bats against lefty pitchers, based on matchups. He said he could do that against Cliff Lee -- who has allowed a career .267 batting average to lefties and a career .257 batting average to righties -- when the Pirates meet the Phillies at the end of July.

"He's a guy I saw last year pitch a lot, and the contrast of left-handed and right-handed batting averages, from a hitting standpoint watching him pitch, I think you take a little bit of the weaponry away with the left-handed bat than the right-handed bat," Hurdle said.

Bucs agree to terms with six Draft picks

HOUSTON -- The Pirates have agreed to terms with six of their draftees, including two top-10 picks.

Pittsburgh agreed to terms with sixth-round pick Dan Gamache and 10th-round pick Taylor Lewis, after agreeing to terms with its 24th, 29th, 30th and 31st-round picks, all of whom played college baseball.

Gamache, an infielder at Auburn, hit .299 with 13 doubles and five home runs as a junior, and .337 during his entire career. He hit .365 as a sophomore, with 15 doubles and eight home runs.

Lewis, an outfielder and team captain at the University of Maine-Orono, finished his junior season with a team-leading 44 runs and a team-high 20 stolen bases in 24 attempts, while hitting .287. He was named to the American East First Team after his sophomore campaign, hitting .369, with 53 runs, 52 RBIs and five home runs.

Brian Sharp, the Pirates' 24th-round pick, hit .352 with 10 home runs in 2011, and is the all-time leader at California Baptist University in runs scored (165) and stolen bases (89).

Bucs bits

• Pittsburgh's Tuesday shutout win marked only the third nine-inning, 1-0 game in Major League history in which 10 pitchers were used.

• Joel Hanrahan is available again on Wednesday. Hurdle said the only time Hanrahan would sit is when he pitches in three consecutive games.

• Wyatt Toregas cleared waivers on Wednesday and has been sent outright to Triple-A Indianapolis.

• Entering Wednesday, starter Charlie Morton has gone 4-0 with a 0.85 ERA in four starts against the National League Central this year.