The Texans practiced without the top two candidates for their starting right tackle job during OTAs and mini-camp.
Derek Newton and Brennan Williams are expected to be ready for training camp on July 26, but it will remain a concern until then for Texans coach Gary Kubiak.
"If you look at our roster, it looks good, but the bottom line is the guys aren't out there, so that's concerning for us as a team and me as a coach," Kubiak said after the conclusion of mini-camp on Thursday. "I love the way Newton has worked. I think he made a lot of progress as a player last year. He played hurt at the end of the year, which was tough on him and us as a team. We drafted a young man with a lot of ability (Williams). He hasn't been out here yet."
Newton, a seventh-round draft pick from Arkansas State in 2011, started 14 games last season. He missed two with a knee injury that required offseason surgery to repair his patellar tendon. Williams, a third-round pick from North Carolina, injured his knee in rookie mini-camp in May.
Ryan Harris, who rotated with Newton for much of last season, and David Quessenberry, a rookie sixth-round pick from San Jose State, were the Texans' top right tackles for much of the spring.
"I like what Ryan has done," Kubiak said. "He's had a good offseason. I like what I see in Quessenberry because he's gotten all the reps. It's all in place, but somebody has to step up and go do it. So, hopefully they're all there when we go back to work."
Right tackle is one of the Texans' biggest concerns heading into training camp, and it's the only real question mark left on the offensive line. Brandon Brooks, a 2012 third-round pick out of Miami (Ohio), has moved into the starting right guard spot this offseason. He'll play alongisde three Pro Bowlers in left tackle Duane Brown, left guard Wade Smith and center Chris Myers.
"(Right tackle) is (a concern)," Kubiak said. "I think it is for the guys up front, too. Our four starters are locked in up front, putting Brandon in with those guys. I think even those guys are looking, thinking, 'OK, who's it going to be? Who's going to step up and take this job and play here for the next 10 years and play right tackle for the Texans?' So I think we're all watching that. I think Newton took a step towards doing that last year, and now he has to take another big step."