Trevor Siemian did something Sunday that Peyton Manning never did in 2015

Not many believed the defending champion Denver Broncos would be 3-0 with Trevor Siemian at quarterback. The former seventh-round pick hadn’t thrown a pass in a regular-season game before 2016 but now looks pretty comfortable under center, especially after Denver’s 29-17 win over the Bengals on Sunday.

It was a breakout performance in Siemian’s young career, completing 23 of 35 attempts for 312 yards and four touchdowns as the Broncos remain perfect this season.

But Sunday’s effort was more than just something special for the 24-year-old quarterback. Siemian’s numbers were better than anything Broncos quarterbacks put up in all of 2015 — yes, topping Peyton Manning and Brock Osweiler.

The most TDs Manning threw in a game last year was three, and he eclipsed 300 yards just twice in nine starts. In seven starts, Osweiler threw three touchdowns and broke 300 yards in a game just once, neither was in the same contest.

Siemian won’t be asked to do a lot this season thanks to the Denver’s stout defense. But if he can build on Sunday’s performance, the Broncos might be in position to defend their title later this season.