MILWAUKEE -- J.D. Martinez, the Astros' 2010 Minor League Player of the Year, made sure that his Major League debut was one to remember.

Martinez hit an RBI double to straightaway center fielder in his first career at-bat -- a pinch-hit appearance in the eighth inning -- in the Astros' 6-2 loss to the Brewers on Saturday night. Martinez arrived at the ballpark about 90 minutes before the first pitch after being called up from Double-A Corpus Christi.

"It was definitely exciting," he said. "You go up there to the plate and my mind was just, 'Hit something hard. Don't embarrass yourself.' I got lucky that he left a fastball middle-away, and I was able to put a good swing on it. My eyes just lit up on it."

Martinez is expected to make his first career start in Sunday's series finale.

"There's a lot of excitement," said Martinez, whose parents flew in from Florida to see his debut. "It's a dream come true, and you work your whole life to get this opportunity. I'm thrilled and excited that they're giving me an opportunity."

Astros manager Brad Mills said that Martinez will play, though it's unclear if he'll play more in right field to replace Hunter Pence or left field when Carlos Lee sees time at first base. Martinez has more experience in left, but says he can play right.

"We're not bringing him up here not to play," Mills said. "We want to see this guy play. We saw how he could swing the bat in Spring Training and he played extremely well."

Martinez, 23, hit .338 with 13 homers and 72 RBIs this year at Corpus Christi after batting .341 with 40 doubles, 18 homers and 89 RBIs combined last year at Class A Lexington and Corpus Christi. He believes he's getting called up at the right time.

"The front office knows what it's doing and how to develop a player," he said. "If they kept me there and wanted me to learn, it's for a reason. I had the confidence in that. I'm not in a rush to get up here. I wanted to be up here, but I wanted to make sure I'm ready. That's the most important thing."

Bourn awaiting fate as Trade Deadline nears

MILWAUKEE -- For the second day in a row, the Astros' clubhouse was filled with anxiety as everyone wondered if more players were on their way out the door. The Astros traded Hunter Pence to the Phillies on Friday and have been in talks with the Braves about outfielder Michael Bourn.

The Giants have shown some interest in Bourn, according to reports, but a baseball source told MLB.com that the Reds backed off Bourn because the asking price was too high. The Astros are looking to land some top prospects in the same fashion that they did with Pence.

Bourn, who went 1-for-4 in Saturday's loss to the Brewers, said he'd prefer to stay in Houston, his hometown.

"Yeah, of course," Bourn said. "I don't control that. There's nothing I can do about that. There's nothing I can say because everybody knew [Hunter] wanted to stay here and he had no control. Sometimes the business side takes over the love side. You've got to understand that."

Bourn was trying to stay focused as much as possible.

"I know it was a little tough for Hunter," Bourn said. "It's a tough thing to deal with all the time. If one of your big pieces leaves, then they're trying to start the whole thing over. That happens from time to time and you have to deal with that. Whatever they decide to do, I'll have to be prepared every day."