The Los Angeles Chargers are pleased with the progress Philip Rivers has made while recovering from his concussion, reports NFL.com's Ian Rapoport. 

This increases his chances of playing Sunday against the Buffalo Bills, but he must be cleared by an independent neurologist before he sees game action. 

Rivers was placed in concussion protocol Monday. Head coach Anthony Lynn said he saw no signs of a concussion Sunday and isn't sure what caused the injury. Rivers finished with 235 yards and two touchdowns Sunday.

If Rivers is unable to play, it will end his consecutive start streak of 185 games, second only to Eli Manning's 208. Kellen Clemens is expected to start in his place if need be.

The Chargers have lost two games in a row and are 3-6.