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7/24/2013 2:10 A.M. ET

Barnes, Martinez day to day with minor injuries

HOUSTON -- Astros manager Bo Porter said he doesn't anticipate having to make a roster move to bring a player up in time for Wednesday afternoon's series finale against the A's despite losing a pair of outfielders Tuesday night to injuries.

Starting center fielder Brandon Barnes left the game after six innings with a mild left calf strain he suffered running the bases in the fifth inning, and starting left fielder J.D. Martinez had a left lower back contusion following a collision with center fielder Justin Maxwell in the ninth inning.

Both players are considered day to day and will be reevaluated before Wednesday's finale.

"I think we should be OK," Porter said. "Both of those guys, it's a bruise and it's one of those things where you don't want to try to push the envelope, especially at the point we were at with J.D. It was the middle of the inning and you're out there holding up the game. It was more a question, 'Can you go right now?' Not, 'Can you go in the next 15 minutes?' We made a decision to get him out of the game, as well."

Barnes, who made yet another terrific diving catch in center field earlier in the game, said his calf was stiff and wasn't so sure it would have enough time to heal in order for him to play Wednesday.

Villar's speed on display in Astros' walk-off

HOUSTON -- The addition of shortstop Jonathan Villar, who made his Major League debut on Monday, at the top of the lineup has given the Astros a much-needed speed element when combined with second baseman Jose Altuve hitting second.

That was on display Tuesday when Villar hit a one-out double in the ninth inning of a 4-4 game and raced around to score the winning run on a botched pickoff attempt by A's catcher Derek Norris. Villar's aggressive play gave the Astros a 5-4 win over Oakland, their first in 11 tries this season.

"Once I saw the ball take off for first base, I knew at least Villar was going to make it to third at that juncture," manager Bo Porter said. "[Norris] threw the ball low and the ball ends up in right field, and Villar just being a baseball player, came all the way home for the game-winning run."

Porter said he plans to leave Villar and Altuve in the first two spots in the batting order for the time being.

"The goal is to try to get Villar as many at-bats as we possibly can between now and the end of the season," Porter said. "He possesses the skill sets you look for in a leadoff hitter. He's not afraid to hit with two strikes, he can play the short game, he's a run-producer and can drive in runs."

Villar certainly can run. He had 16 doubles, eight triples and 31 stolen bases in 90 games at Triple-A Oklahoma City. Altuve, meanwhile, entered Tuesday with 22 stolen bases, which ranked fourth in the American League.

"The more guys you have in your everyday lineup that can steal bases or go first to third, it puts more pressure on the defense," Porter said. "It seems as you start to look around and have Villar and Altuve and [Brandon] Barnes and [Justin] Maxwell, you have some guys that push the envelope and put pressure on opposing pitchers."

Hall of Fame broadcaster Hamilton discusses health

HOUSTON -- Hall of Fame broadcaster Milo Hamilton, who retired from calling games following last season, met with the media Tuesday afternoon and provided an update on his health, as well as his plans for the immediate future.

Hamilton, who's battled chronic lymphocytic leukemia since 1974, said he's back on regular chemotherapy treatments that have cut into his schedule. Hamilton had hoped to return to the booth this year to call a game from his 60th Major League ballpark, but he said he can no longer fly.

"You've heard me talk about it for two years, that I wanted to get to 60 ballparks, but they're not letting me get on an airplane anymore," he said. "I guess I'm going to have to settle for a pair of 59s -- 59 years in the big leagues and 59 ballparks, but I'll take it."

Hamilton, 85, called a game from Marlins Park last year, which was his 59th. He quit traveling with the team full-time several years ago and had been calling only home games until last year. He had hoped to travel to Detroit's Comerica Park earlier this year, or early next month to Minnesota's Target Field.

"I'm disappointed, because maybe I made too much out of it that I wanted to have 60 ballparks," he said. "I thought it was a nice round number. It's only a disappointment to me, probably. I would have loved to have done it. I wanted to see those parks."

Hamilton's broadcasting career has spanned nearly 70 years, and more than 55 in the Major Leagues. He still serves as a special adviser to owner Jim Crane and president of business operations Reid Ryan, as well as doing commercials and occasional talk show appearances.

"My big next goal is to have 70 years on the air, and if I can make it to 2015, there it will be," he said.

Reid, Nolan Ryan coming to a grill near you

HOUSTON -- Fans in Houston could soon get the chance to see Astros president of business operations Reid Ryan dueling with his father, Nolan Ryan, over a hot grill.

The Ryan family shot a commercial earlier this summer in the family's ranch in central Texas for Nolan Ryan Beef. Reid Ryan's family was shown wearing Astros gear and Nolan Ryan was wearing Rangers gear while showing his son the best way to cook meat.

"It pits father versus son, old school versus new school," Reid said. "It's filmed at our ranch and involves my dad cooking Nolan Ryan Beef and me using an off-brand and him sharing his hot dogs. We light our grills, we do our stuff differently, but in the end, Nolan Ryan Beef brings the families together."

Reid said the commercial is running during Rangers broadcasts and could be seen on Astros broadcasts, too.

"It's really neat," he said. "It makes those kinds of times fun. They're airing it on Rangers games right now, and hopefully Nolan Ryan Beef will start airing it in this market, because fans will really like it."

Ryan, the eldest son of the Hall of Fame hurler, was named Houston's president of business operations in May. Nolan is the president of the Rangers.

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.