Updated

HOUSTON (AP) — Brian Cushing was back on the football field Monday, glad to have a diversion from his recent problems.

The Houston linebacker took part in the Texans' first offseason team practice after spending the last several days dealing with the fallout of his positive test for using a performance-enhancing drug. He will be suspended for the first four games of the upcoming season.

Cushing said it was good to be "thinking about something else" and that he was happy to be with his teammates. He said the reaction from them has been positive.

"Everyone's happy and everyone understands the situation, so they're all behind me and this doesn't change anything," he said.

Coach Gary Kubiak was among those excited to see Cushing at practice.

"He's all business, which I expected him to be," Kubiak said. "I know it's been a rough week and it was nice to see him back on the field."

Cushing confirmed last week that he tested positive last September for HCG, a fertility drug that is on the league's banned substance list. He said he never took a banned substance and has no idea how the positive test happened. Many fans and some in the media weren't satisfied with his explanation for the failed drug test, but Cushing isn't too concerned about that.

"I really didn't pay attention too much to the reaction or anything," he said. "I felt that I got everything off my chest I needed to and just pretty much explained myself in full detail. People can think what they want, but the truth is out there."

Cushing had 133 tackles for the Texans last season to win The Associated Press Defensive Rookie of the Year award and retained it after a revote last week following his suspension.

He said he doesn't believe he has to prove himself after his suspension and is looking to play better next season.

"I don't feel there's a limit right now," he said. "I think it's out there for me to go grab and no one's going to stop me from working toward that."

Cushing can participate in offseason practices and activities but the Texans will start the season without their starting strong side linebacker. They signed veteran Danny Clark last week and he is ready to fill in while Cushing is out.

"They have a time limit of four games, but I've got a longer stretch in mind," Clark said. "I plan on helping this team all year long, all the way into the playoffs and hopefully the Super Bowl."

Clark has played strong side linebacker for most of his career, but can play at any of the linebacker spots. He had to show that skill on Monday with star middle linebacker DeMeco Ryans sitting out with a hamstring injury. Fellow strong side linebacker Kevin Bentley had back spasms and also missed practice.

Kubiak was impressed with Clark, who spent the last two seasons with the Giants after playing for Houston in 2007. Clark started 26 games over the last two seasons for the Giants and eight games in his season in Houston.

Bentley and Xavier Adibi will also compete for Cushing's spot while he is out. Kubiak noted that Adibi added some weight in the offseason which could help him this season. He missed several games as a rookie because of health concerns but appeared in each game last season.