Trevor Ariza strolled into a middle school gym, stopping to shake hands, give high-fives and pose for pictures.

He wore a bright red Rockets T-shirt and a big grin as he sat with sixth- and seventh-graders to play chess against American Grandmaster Susan Polgar as part of a Rockets community event.

Ariza, who is beginning his second stint with the Rockets after being acquired from the Washington Wizards in a sign-and-trade deal in July, was visibly gleeful and comfortable among Rockets staff and the community members on this Monday afternoon. That's the mood he has been in since his return to Houston, the city he calls his second home.

The 10-year NBA veteran spent the last two seasons in Washington, and when the free-agency period rolled around over the summer, he had a few options: his hometown of Los Angeles with the rebuilding Lakers; Dallas, where he could play alongside Dirk Nowitzki, one of the league's top veterans; and Washington, where he had become a key leader for the up-and-coming Wizards.

"Houston is like my second home," Ariza said, "and I liked what was happening here - the pieces that are here, the big goals they had set.

"Plus I love this city. I love the people. I love the weather. I love it here. I'm so happy to be back."

Ariza spent the 2009-10 season with the Rockets and had the highest scoring average of his career with 14.9 points per game. He also averaged 5.6 rebounds and 3.8 assists that season.

Last season with the Wizards, Ariza averaged 14.4 points and 6.2 rebounds. His defensive play over the last several seasons is what defined him most, however, and that is what he hopes to bring to the table this season.

"We are going to be a better defensive team this year," Rockets general manager Daryl Morey said. "Trevor is a great defender, and we have two of the best defenders (Dwight Howard and Pat Beverley) in the starting five already."

One of them, Howard, has a history with Ariza. They played together with the Orlando Magic during the 2005-06 and 2006-07 seasons.

Ariza also knows James Harden well. Although Ariza is older, they both played high school basketball in Los Angeles, and Ariza played in college at UCLA, watching a young Harden progress.

"It makes it easier that we know each other," Ariza said. "I think we will be able get things together quicker. We will be able to hold each other accountable."

As for the other players, Ariza has made a point to reach out to his new teammates. Troy Daniels said that when Ariza first arrived in Houston, Ariza called him to get together.

"He has come and worked out with some of the younger guys, too," Daniels said. "I think that says a lot about a vet who will come and spend time in the gym with us."

Within a short time, Ariza has established himself as a leader. After his time in Washington, it's a role he is comfortable with.

"I noticed that I could have a positive effect on people during my time in Washington," he said. "I watched the younger players around me grow, and it was a satisfying thing to see and a great feeling to know that I had something to do with it."