Texans left tackle Duane Brown has joined outside linebacker Brian Cushing on the NFL’s suspended list.

Brown was suspended for four games today for violating the league’s policy against performance-enhancing drugs. His suspension comes at a bad time because the unbeaten Texans are hosting the Dallas Cowboys and outside linebacker DeMarcus Ware, one of the NFL’s premier pass rushers.

Brown will be replaced by Rashad Butler. Butler’s role as the swing tackle behind Brown and right tackle Eric Winston will be taken by Ephraim Salaam, who will be signed for his third tour of duty with the Texans.

Brown will be eligible to return after the Kansas City game on Oct. 17.

“First off, I want to personally apologize to (owner Bob) Mr. McNair, coach (Gary) Kubiak and the rest of the coaching staff, my teammates, family and to all the great and loyal Texans fans,” Brown said in a statement. “I take full responsibility for putting myself in this situation. I unknowingly took a supplement tainted with a banned substance and now have to deal with the consequences.”

If Brown had filed an appeal, he could have continued to play until commissioner Roger Goodell made a ruling.

“After reviewing the appeal process and speaking with legal counsel, I have decided not to appeal my suspension,” Brown said. “I understand the rules and accept my punishment. I vow to learn from this mistake and be a better player and teammate because of it.”

Brown was the team’s first-round draft choice in 2008. He was mentored that season by Salaam, who had helped mentor Charles Spencer in 2006.

“We are disappointed that Duane Brown has been suspended,” general manager Rick Smith said in a statement. “This is a significant blow to our team. 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.

“Our head athletic trainer (Geoff Kaplan), head strength and conditioning coach (Cedric Smith) as well as our team nutritionist (Roberta Anding) 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.

“I am confident in our coaches and our players that we will work through this adversity and continue to play winning football.”