As they had done hundreds of times throughout the years, Rob and Patti Grossman got into their car early Wednesday morning and took their kid to his baseball game. The destination wasn’t Queenston, Cy-Fair Fields, Baseball U.S.A. or any of the dozens of diamonds where Robbie Grossman developed his skills in the Houston area. This trip was different, better, special. The Grossmans headed where many Little Leaguers in Houston dream of playing one day. They dropped Robbie off outside Minute Maid Park with a simple message from Mom: “Just go play ball.” “I plan to,” replied Robbie Grossman, a lifelong fan of the Astros. Twenty years after he declared to his parents he would become an Astro, Grossman, 23, made his major league debut with two doubles while helping the Astros beat the Seattle Mariners 10-3 on Wednesday before a matinee crowd of 11,686. Grossman was 2-for-5 with a run, becoming the second Astro to debut in the majors with at least two doubles. James Mouton was the first on April 4, 1994, against Montreal. “What more can you ask for?” Astros manager Bo Porter said. “Two doubles; you get to make your major league debut at home in front of your parents and friends. I took him the lineup card and gave it to him, so he’s happy about that. We were able to retrieve his first hit, and he also caught the last out, and I told him to keep the ball. “We’re pretty excited for him. He adds a dynamic to our club, some more speed at the top of the lineup and a guy that gets on base.” Grossman appreciated the keepsakes. “I’m probably going to put them in my room at my parents’ house,” he said. Less than 12 hours after he was informed he had 30 minutes to get to the Albuquerque airport for his first call-up to the majors, the Cy-Fair High graduate was hitting inside the Minute Maid Park batting cage. Before Wednesday, Grossman had been on the Minute Maid Park diamond only once. He and his Cy-Fair teammates were allowed to hold a giant American flag during the national anthem as a treat for winning the 2007 state title. “I always watched the Killer B’s, of course — (Jeff) Bagwell, (Craig) Biggio and (Lance) Berkman,” he said. “It’s exciting to put on this uniform. I grew up cheering for this team. This is a special time for me and my family.” The Grossmans, who are considering making a trip to Boston this weekend to watch their son play against the Red Sox at Fenway Park, met in San Diego and moved to Cypress in 1991 when Robbie was a toddler. With no friends in the area when they moved here, they spent a lot of their free time early on watching the Astros play. “Ever since he was a little kid, we were taking him to the Astrodome,” Rob Grossman said. “He was 3 years old, and he said, ‘I want to be an Astro.’