HOUSTON—After a loss to the lowly Houston Texans on Sunday, Los Angeles Chargers coach Brandon Staley was quick to remind his players they still have plenty to play for. “This is the tough side of the NFL,” Staley said. “It’s been a fight this entire season for us. It’s going to continue to be that way. We still have a lot in front of us.” Rex Burkhead ran for a career-high 149 yards and two touchdowns, and the Texans took advantage of three turnovers to beat the Chargers 41-29 with both teams missing more than a dozen players because COVID-19 protocols. The Chargers’ playoff chances took a serious blow with the loss. Outside linebacker Joey Bosa, running back Austin Ekeler, receiver Mike Williams and center Corey Linsley were among the major contributors on the COVID-19 list for LA (8-7), which entered in second place in the AFC West. “We had …