MIAMI (CBSMiami.com) – Statistically, Denver Broncos quarterback Tim Tebow is one of the worst passers in the league; and that may cost him playing time when the Broncos host the Pittsburgh Steelers.

According to profootballtalk.com, backup quarterback Brady Quinn is getting roughly half of the first-string snaps during practice leading up to the Steelers game.

But, it’s unknown whether Quinn will actually play on Sunday, the website reported.

Quinn hasn’t thrown a pass in a regular-season game since 2009 when he was a member of the Cleveland Browns.

Tebow reeled off a 7-1 record heading into the final three games of the season and while he couldn’t throw the football, still produced victories.

But, over the last three weeks, Tebow has struggled to keep his team in contention during a three-game losing streak.

During the three straight losses, Tebow completed just 41 percent of his passes and was absolutely abysmal in the final game of the regular season.

Against an average Kansas City Chiefs offense, Tebow completed just 6 of 22 passes for 60 yards and one interception.

Now, Tebow will be facing his toughest challenge to date in the NFL as a starter.

The Steelers have the toughest defense in the NFL, ranking first in both points allowed and yards allowed. The Steelers finished the season winning five of their final six games.

During the Steelers’ streak, they are giving up less than 10 points per game.

But, the Steelers are coming into the game at less than full-strength.

Quarterback Ben Roethlisberger has been banged up with an ankle injury, center Maurkice Pouncey is out, and safety Ryan Clark can’t play due to the interaction with the mile-high air and his sickle cell trait.