An observation and prediction with seven practices, including a three-day minicamp, left in the Texans’ offseason program: They have a problem at right offensive tackle. Brooks Reed will start at outside linebacker when the Texans begin the regular season at San Diego. First, let’s look at right tackle. Derek Newton, the returning starter, and Brennan Williams, the first pick in the third round, are sidelined because of knee injuries. During organized team activities, Newton and Williams have spent so much time on stationary bikes they look as if they are preparing for the Tour de France. Newton is recovering from surgery to repair a patellar dislocation. Williams, who is supposed to challenge Newton for the starting job, suffered a minor knee injury on the second day of rookie minicamp and has been reduced to being a spectator.