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5/28/2013 3:10 P.M. ET

Astros hoping walk-off wins are contagious

HOUSTON -- If anyone knows how much of a boost a walk-off win can be to a team, it's Astros pitcher Travis Blackley. The Aussie spent the majority of the season last year with the A's, who had 14 walk-off wins in the regular season en route to the American League West title.

"When you start to do it, you believe any time you can come over the top of somebody, and it makes you harder to beat," Blackley said. "The other team knows you're capable of that, knows that you like pressure. Oakland is a massive pressure team late in the game -- look at what they just did to us in the first of the series [when the A's scored three in the ninth to win, 6-5, on Friday].

"We had them dead to rights, and in one inning, they just kind of put something together. That's what they believe they have, and that's what we need to get."

Houston's 12-inning win over the Rockies on Monday was only its third walk-off win in the last two seasons.

"They're contagious, and if we nailed down another today, we'll come home next week and probably have another," Blackley said. "They come in bunches. And that helped the A's last year. We had four in one homestand, two of them against the Yankees in a four-game set. That's ridiculous. That lets you know can beat anybody. You can take anybody's closer down, just because you believe. That's huge."

Barnes ready to answer call of full-time duty

HOUSTON -- With the Astros having sent Robbie Grossman back to Triple-A on Monday, rookie outfielder Brandon Barnes stands to get more playing time in center field. He'll have a chance to show what he can do on a full-time basis before Justin Maxwell returns from his fractured hand next month.

Barnes, who won Monday's game against the Rockies with a walk-off hit in the 12th inning, had started 18 games entering Tuesday, mostly against left-handed starters. He was hitting .258 against right-handers and .382 against left-handers, and .323 overall, which ranked second among rookies with at least 60 plate appearances.

"The opportunity is great and I'm very appreciative," Barnes said. "I'm still going to go about the job the same way and still work hard."

Barnes has shown a knack for coming up with big plays in limited playing time, making a game-winning catch at the wall two weeks ago in the ninth inning in Detroit, and throwing out a runner at the plate in Pittsburgh a few days later. His walk-off hit on Monday was the first of his career.

"There are several questions I have from a managerial standpoint and several questions we as an organization want to get answers to," manager Bo Porter said. "Brandon Barnes is another one of those questions. Can he play every day between now and the time Justin Maxwell comes back? We're going to find out whether or not he's able to do that. I'm going to run him out there against righties and lefties, and give him an opportunity to answer those questions."

The biggest question is whether Barnes can handle right-handed pitching on a consistent basis.

"He's never been given that opportunity," Porter said. "I've been open and honest with him about communicating as it relates to that. I told him to stay ready, because you never know when an opportunity is going to present itself, and we find out we need an extra pitcher, and here it is."

Right-hander Peacock recalled by Astros

HOUSTON -- The Astros recalled right-handed pitcher Brad Peacock from Triple-A Oklahoma City prior to Tuesday's game against the Rockies, taking the roster spot of outfielder Robbie Grossman, who was optioned to the Minor Leagues on Monday.

Manager Bo Porter said the move was made to give Houston another pitcher as it heads to Coors Field on Wednesday, and not because of Grossman's performance. He was hitting .198 with a .310 on-base percentage while starting 26 of 28 games for the Astros.

"[General manager] Jeff [Luhnow] and I both talked to him and said, 'This is a great experience for you,'" Porter said. "'You will learn from this experience, and it had more to do with us needing a starting pitcher than your performance.' I said to him, 'When we committed to you playing every day, the reason we made that commitment is we feel like you're an everyday player. We want you to go down there and continue to grow, and think about the things you've learned here, and we know you'll be here in a short time and continue to help this ballclub.'"

Peacock began the season in the Astros' starting rotation, but was sent down after going 1-3 with a 9.41 ERA in six games (five starts). He went 1-2 with a 4.98 ERA in four starts for the RedHawks, allowing 18 hits and striking out 27 batters in 21 2/3 innings. He'll be used in relief.

"He's done a good job down there," Porter said. "He was getting in the groove in Triple-A and it was more about us needing an extra arm at this time, with the bullpen being taxed and us heading to Colorado. You don't want to go into a [two-game] series in Colorado [shorthanded], and we don't have an off-day anywhere in sight. We want to make sure we have enough coverage."

The Astros preached fastball command to Peacock, who was working on refining his two-seamer and his slider, and slowing everything down while with the RedHawks.

"I'm excited to be here," he said. "Whatever I can do to help the team, I'm here for it. I've been working on a lot of stuff and I feel good."

Dierker ready to make difference for Astros

HOUSTON -- Larry Dierker met with reporters on Tuesday wearing one of his trademark Hawaiian shirts, standing just a couple of feet away from a picture of him blowing out candles on his 18th birthday -- the day he made his Major League debut for the Colt .45s on Sept. 22, 1964.

Dierker has been a part of the Astros organization for nearly a half-century, though a recent public breakup forced him to have sleepless nights. Now that he's back with the club as a special assistant to president of business operations Reid Ryan, Dierker is sleeping better these days, and he is eager to help the Astros get to where they need to be.

Ryan brought Dierker -- the popular former pitcher, broadcaster and manager -- back to the family last week after he had turned down a job offer from the club earlier this year, one he thought was too structured and not fulfilling.

"It was a very awkward feeling to feel I didn't want to do what they wanted me to do, and also to have the flexibility to say, 'No,'" Dierker said. "For about a week, I was having trouble sleeping. I'm sleeping pretty good now."

Tuesday marked Dierker's first day on the job, and he spent it meeting with Ryan as well as shaking hands with fans at Larry's Big Bamboo Bar at Minute Maid Park. He'll be making public appearances throughout the season, writing for the team's game program and lending a hand wherever Ryan sees a need for it.

"I wanted to do something that has more impact, something more important than showing up every time we get a certain amount of people together," Dierker said. "I think that's ultimately what I'm going to end up doing, to be honest, but it's a little flexible at this point. I know I have things I can add from my perspective that [Ryan] may not have encountered at the Triple-A level.

"Most of it is not going to be in the baseball area; most of it is going to be building an image for the fans, building within the organization, so we constantly have our best foot forward instead of being caught in a PR dilemma as we have a few times recently. What it grows into, I don't know. I hope it will grow into something more next year."

Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.