Broncos' Siemian clutch with 2 TD drives in 4th

playTrevor Siemian talks about bouncing back from early interceptions to lead the Broncos to a win over the Panthers and how he thanks the team's coaching for having him prepared for the game. (1:20)DENVER -- In the end Trevor Siemian didn't throw for 180 yards in his first NFL start, he did throw two interceptions and it wasn't always a smooth ride on the learning curve.

But the 24-year-old never lost his composure and showed why Broncos coach Gary Kubiak picked him as Peyton Manning's replacement in a tense 21-20 victory over the Carolina Panthers Thursday night.

"Sure, there's butterflies every time you play,'' Siemian said. "I think something is wrong with you if you don't. I'm just super…