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04/09/2013 2:53 AM ET

Porter pulls Martinez after mental error

SEATTLE -- Astros manager Bo Porter pulled starting left fielder J.D. Martinez in the middle of the fourth inning Monday night in response to what Martinez later admitted to be a mental mistake during his at-bat in the top of the inning, a popout to second base.

Porter was asked following the Astros' 3-0 loss to the Mariners if Martinez, who was hitting cleanup for the first time this year, had been injured, and he told reporters to ask Martinez what happened.

"That was a manager's decision," Porter said. "You go ask him why he didn't finish the game. I'm actually interested in what he's going to tell you."

Martinez admitted to making a mistake during the at-bat, but wouldn't go much beyond that. He swung at a first-pitch fastball from Joe Saunders and popped out after striking out looking in the first inning. Designated hitter Chris Carter swung at the first pitch the at-bat prior to Martinez, too.

"From a baseball standpoint, I made a mistake today," Martinez said. "I had a mental error going up to the plate and was totally my fault. I understand everything that Bo did, taking me out and everything. I hold nothing against him, in that sense, because what I did was unacceptable and it was just a mental mistake that will never happen again."

Martinez hinted that he went against the approach that was discussed at the hitter's meeting prior to the game.

"It was just something going up to the plate, our plan and everything," he said. "I got caught in the moment and really didn't take a step back. The game was moving quick, and I totally slipped, and I take full responsibility for it."

Martinez has no problem with how Porter handled the situation.

"I completely get it," he said. "I don't want it to come off as me being selfish and not being about the team. That's not what my intentions were. You just get caught up in the game sometimes and you want to go up there and you want to hit so bad and your plan sometimes just flies out the window."

Determined Clemens honored by first callup

SEATTLE -- Newest Astros pitcher Paul Clemens was leaning on the dugout railing in the sixth inning of an otherwise routine early-season Triple-A game in Memphis on Sunday afternoon when RedHawks manager Tony DeFrancesco asked him to come down and see him.

"He said, 'You're going to The Show,'" Clemens said. "It's a surreal moment, but I tried to take 20 minutes to sit down and let that soak in. Now I'm ready to get back to work."

Clemens shook hands with his teammates, jumped on a plane for Seattle and arrived at 1 a.m. PT on Monday, but the trip was worth it. Clemens, a starter by trade, will work in the Houston bullpen and he said the chance to wear a Major League uniform is a dream come true.

"It took a lot of hard work and dedication," he said. "I have to give thanks to all the coaches I had coming up. I'm not the kind of guy who just gets to the Major Leagues on my own. That being said, I have to thank guys like [Braves Minor League pitching coaches] Gabe Luckert, Derrick Lewis, Marty Reed and Derek Botelho. I was just a sponge soaking up knowledge, being traded over here and being polished by guys like Don Alexander and Doug Brocail, it's just been flat-out amazing."

Clemens is likeable and humble, but is confident in his abilities and his power stuff.

"I'm a self-aware man," he said. "I know what I had to do to get here, and now it's a dream come true and this is honestly the first stop. I want to be a guy Bo Porter can look at and say, 'That's the guy I want coming in the game to lock something down.' Whatever they ask me to do, I'm going to do to my full abilities."

Porter, the Astros' manager, said he wouldn't be afraid to use Clemens in any situation.

"He did a great job in spring when he started some games, and he pitched in relief in the bullpen," he said. "It gives us great flexibility being built up as a starter. You can bring him in long situations, you can bring him into short situations because he has swing-and-miss stuff."

Maxwell is rewarding Porter's faith

SEATTLE -- Astros center fielder Justin Maxwell struggled mightily at the plate this spring, hitting just .153, but manager Bo Porter never flinched. He remained committed to the promising youngster and was confident he was going to be able perform when the season started.

Maxwell has done just that through one week of the season. He entered Monday's game against the Mariners hitting .381 with two RBIs and a pair of triples, and he singled in his first at-bat Monday. He's also played Gold Glove-caliber center field.

"That's why a lot of times you look at Spring Training numbers, and I think I said this even in the spring, you looked at his numbers and he's hitting a buck something and I go, 'I'm not worried about it,'" he said. "If you looked, he was putting together some of the best swings we had on the team.

"You look at the numbers of balls he put in play hard, and he had a high percentage, and now he's putting the same swings on the ball and he's getting hits, and defensively he's one of the best players in baseball."

When asked if he was the most athletic player on the team, Porter quipped: "If you're taking roll, his name could be at the top of the chart," he said.

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.