The Denver Broncos might not have said it, but they definitely wanted Paxton Lynch to win the starting quarterback job this offseason after using a first-round pick on him in 2015. It's not going to happen. 

Vance Joseph has played it coy as both Lynch and Trevor Siemian failed to wow throughout camp, refusing to name a starter or give anyone the lead in the battle. But there was a single play on Saturday night where this became abundantly clear. You can never distill a quarterback battle to one throw from one contestant, but Lynch missing Demaryius Thomas on a key third down  against the 49ers -- his sixth play on offense -- was an all-timer in terms of making it obvious he isn't ready to start for Denver.

On the previous play, Lynch held the ball too long and missed badly on a throw outside to Thomas. That set up the Broncos on a 3rd-and-6. Denver lined up two receivers, including Thomas, snug on the right side with tight end Virgil Green and another wideout on the left side.

via NFL Game Pass

Three of the four pass catchers ran deep routes (which essentially function as clear-out routes in this case) with Thomas running an underneath crosser. By the time that Thomas got to the midfield logo, Lynch had not made a decision on where to throw. 

Well, he had -- he was going to throw the ball downfield to Green, despite the fact that Thomas couldn't have been more wide open if he was dropped from the sky onto the field. 

And Lynch couldn't have been more oblivious. 

via NFL Game Pass

Instead of going to Thomas (black circle) -- who is one of the most productive receivers in Broncos history, the clear-cut No. 1 option on this team and a guy streaking across the field wide open with an opportunity to catch a simple pass, turn and pick up an easy first down -- Lynch looked down the field for Green (yellow), who was covered by two guys.

via NFL Game Pass

This isn't hindsight or an attempt to dog Lynch. I really like him as a player, at least from a physical specimen perspective. But this is a really, really bad miss. Lynch knows that Thomas is, at worst, his bail-out option here. Green is covered by two guys and Thomas is streaking wide open. 

Lynch is even looking in the same area of the field, but he's clearly just locked into one option and not reading the field. Lynch would finish 9-of-13 for 39 yards in an extremely unimpressive effort.

By contrast, Trevor Siemian came in and immediately marched the Broncos down for a touchdown. Even after a 9-yard score to rookie running back DeAngelo Henderson was called back for holding, Siemian hit Jordan Taylor for a 19-yard score. Neither of the passes were Siemian overpowering a defense with his am strength. But he made good throws and allowed his guys to go make plays. He might not necessarily elevate the guys around him, but he will allow the guys around him to elevate him when he plays. 

The same cannot be said for Lynch right now, which makes him a liability as a starting quarterback. There is almost no chance the Broncos can consider going with the former first-round pick to start the season barring an absolutely unprecedented 180 over the next week or so of preseason action.