Houston left tackle Duane Brown was suspended Tuesday for four games without pay for violating the NFL's policy on performance enhancing drugs, joining linebacker Brian Cushing on the sideline for the same infraction.

Brown, the Texans' first-round draft choice and the 26th overall pick in 2008, said he wouldn't appeal the suspension, meaning his next game will be Nov. 1 at Indianapolis. He will miss the undefeated Texans' home showdown Sunday with the Dallas Cowboys and the next three games.

Brown apologized to the team's owners, coaches, fans and his teammates.

"I take full responsibility for putting myself in this situation," he said. "I unknowingly took a supplement tainted with a banned substance and now have to deal with the consequences. After reviewing the appeal process and speaking with legal counsel, I have decided not to appeal my suspension. I understand the rules and accept my punishment."

The team didn't identify the supplement.

General manager Rick Smith said the team was disappointed and called the suspension "a significant blow."

"Our players have to understand that they are responsible for what goes into their bodies and that they take risks anytime they use a supplement not approved by the NFL," he said in a statement released by the Texans. "Our head athletic trainer, head strength and conditioning coach as well as our team nutritionist have had many meetings and presentations constantly reminding our players about the dangers of the supplement industry and risks associated with taking non-approved products."

Right tackle Eric Winston said the Texans have raised awareness among the players about the risks of using supplements since Cushing was punished.

"We talk about it, there are signs up in the locker room," Winston said. "There are all kinds of things, but it's an industry problem, too. They can put whatever they want in there. There's no regulation to it. Until there is something done about that, these things are going to happen."

Team owner Bob McNair had no comment on the suspension. Brown had started all 34 games since he was drafted, and the timing of his punishment could hardly be worse.

The Texans are aiming for their first 3-0 start and a validating victory over the high-profile Cowboys, who still get most of the attention in the state.

"You never want to have to deal with this too much," Winston said. "But that's the adversity we're dealt right now, and we're just going to have to keep moving forward as a team. Everyone is going to have to play better and just pick up the leftovers."

The Texans reacquired tackle Ephraim Salaam after announcing Brown's punishment, according to Salaam's agent, Joby Branyon. The 34-year-old Salaam played for Houston in 2006-08.

"It feels good to be home," Salaam told KRIV-TV. "I plan to bring some veteran leadership. You always want to have guys who have been through the fires."

Brown has the crucial role of protecting the blind side of Texans quarterback Matt Schaub. Brown held his own in a season-opening battle with Colts All-Pro end Dwight Freeney. Rashad Butler, in his fifth season, will make his first career start in Brown's place on Sunday.

"I feel sad and disappointed to hear about Duane and his situation," Butler told KRIV-TV. "I know Duane will serve his four-game suspension and will come back even more hungry than before.

"The team has to go on," Butler said. "Coach (Gary) Kubiak and (offensive line coach) John Benton have given me a great opportunity to fill his shoes."

Butler played in all 16 games last season and the first two of 2010.

"Rashad's a good player. He wouldn't be on this team if he wasn't," Winston said. "He's very capable, and he's probably looking forward to the chance to go out and play, and play well."

The Texans have gotten by so far without Cushing, the star linebacker who was suspended for four games for the same infraction. He is eligible to return Oct. 10, when Houston hosts the New York Giants.

Cushing, last year's Associated Press Defensive Rookie of the Year, was suspended in May for testing positive for HCG, a fertility drug that is on the NFL's banned substances list.

Cushing met with several doctors over the summer, and said some concluded that his positive test resulted from overtraining. McNair met with NFL Commissioner Roger Goodell in New York to plead his case, but the league upheld Cushing's suspension.