Philip Rivers will be without both his starting offensive tackles against the Pittsburgh Steelers after the Indianapolis Colts confirmed Anthony Castonzo will miss the Week 16 game.

Castonzo was ruled out on Saturday due to a “knee/ankle” injury, joining Braden Smith on the sidelines. Smith was placed on the reserve/COVID-19 list on Friday.

The news will be a blow for veteran quarterback Rivers as he prepares to face a Steelers defense that leads the NFL in sacks this year with 47.

Rivers has played three games without one of Castonzo or Smith this season and was sacked five times across those fixtures. In his 11 outings with the duo he has been sacked nine times.

Among quarterbacks to have started more than six games this season, only Ben Roethlisberger (12) and Drew Brees (11) have been sacked fewer times than Rivers (14), but he may now feel more exposed.

The Steelers have already clinched a playoff spot but will be looking to end a three-game losing streak at Heinz Field, where victory would see them secure the AFC North division title.

However, Indianapolis will be hoping to pile more misery on the Steelers and could book their place in the postseason with a win.