Case Keenum, an undrafted free agent who has never played in an NFL game, will start Sunday at quarterback for the Houston Texans at the undefeated Kansas City Chiefs.Coach Gary Kubiak says Matt Schaub, who is dealing with injuries to his right ankle and foot, won’t play this week. Keenum was a record-setting quarterback at the University of Houston before spending last season on the practice squad. The Texans (2-4) have lost four straight games while being hurt by penalties, turnovers and other mistakes. Kubiak chose to go with Keenum over backup T.J. Yates, who led Houston to its first playoff win two years ago when Schaub was hurt. Vick won’t playQuarterback Nick Foles will start his second consecutive game for the Eagles, on Sunday against the Dallas Cowboys, according to Michael Vick.Vick declared himself out of Sunday’s game, an expected eventuality that came in the form of an unexpected announcement.“No, I’m not playing this week,” Vick said Thursday.Vick declared his status two hours after Eagles coach Chip Kelly would not yet rule out Vick.Briefly • Broncos: Linebacker Von Miller participated in his first practice since serving a six-game suspension for violating the NFL’s substance-abuse policy. • 49ers: Receiver Chris Harper, a fourth-round draft pick by Seattle in April, was released.