Richardson (oblique) will be inactive for Sunday's game against the Titans as the emergency No. 3 quarterback while Joe Flacco receives a second straight start, Adam Schefter of ESPN reports.
Richardson sat out the Colts' Week 5 loss to the Jaguars with the oblique injury, but reports leading up to Sunday's contest suggested that the second-year quarterback -- who had been listed as questionable -- was on track to start Week 6 after turning in a pair of limited practices as well as a full session this week. However, with Richardson not yet 100 percent healthy, the Colts will err on the side of caution and hold him out for a second straight week while Flacco starts and Sam Ehlinger serves as his top backup. A source told Jordan Schultz of Fox Sports that Richardson would be available to play if the Colts were playing a playoff game, a sign that the 22-year-old will likely be back in the lineup next Sunday against the Dolphins if he avoids any setbacks during the upcoming week.