SCOTTSDALE, Ariz. (TNS) — The oddsmakers have spoken.

Shortly after reports surfaced that UCLA quarterback Josh Rosen will miss the Cactus Bowl while he recovers from his second concussion of the season, K-State became a 6.5-point favorite in the game. The Wildcats were favored by three when the postseason matchup was announced, and that number dropped half a point when signs pointed toward Rosen playing. Now that he's unlikely to suit up, the odds clearly favor K-State.

It's easy to understand why.

Rosen is one of the best passers in all of college football. Should he choose to declare for the NFL Draft after the Cactus Bowl, he is expected to be a first-round pick. He threw for 3,668 yards and 23 touchdowns this season, including five 400-yard games and an epic come-from-behind victory over Texas A&M on opening weekend. On Saturday, Rosen said he wanted to play in the Cactus Bowl, with UCLA interim coach Jedd Fisch describing him as a game-time decision. A few hours later, reports said he was ruled out for the game.

There will be a dropoff with backup Devon Modster taking the snaps. How much of a dropoff? That's the question.

"He is a very talented deep-ball passer," Fisch said. "He gets the ball out of his hands quickly. He can read defenses well. He plays very mature, very poised, very smart. He is exciting to coach as a redshirt freshman. He has been the No. 2 since we got here, so he has had a gazillion reps. He has really been watching and following Josh. His improvement has been tremendous, and I think he is going to give us a great chance to succeed."

A former four-star recruit and top 200 national prospect, the dual-threat quarterback held the offense together after Rosen was knocked out of the Bruins' season-finale against California. He helped them qualify for the postseason.

If you add up all his playing time this season in relief of Rosen — late in a blowout win over Hawaii, and meaningful duty against Utah and Cal — Fisch says it is like he has played in two full games.

With Rosen questionable to play, UCLA has split first-team reps between Rosen and Modster throughout bowl practices.

"Whichever guy plays," Fisch said, "we will be ready."

Snyder has seen enough of UCLA's offense to respect the Bruins, even with a backup quarterback.

"They have been a little bit more down-the-field oriented than some of the teams in our league," Snyder said. "So many teams in our league rise up and throw it out there real quick. UCLA does that, but not as much of it. With them, it's more down-the-field stuff. They utilize their tight ends very heavily, and their running backs. It is a very good offense in terms of passing game, because they involve everybody extremely well."

Another issue: K-State has not defended the pass well this season, allowing 310.2 yards per game. It surrendered at least 291 passing yards to every quarterback it faced in Big 12 play. Perhaps the Wildcats will perform better against a backup quarterback. Then again, they surrendered 410 yards and a touchdown to KU quarterback Carter Stanley, and he was promoted from backup to starter for that game.

K-State cornerback Duke Shelley isn't taking anything for granted. So what if the oddsmakers like K-State more now? He witnessed first-hand how K-State's offense survived after Jesse Ertz and Alex Delton went down with injuries, only for freshman Skylar Thompson to lead the team to four wins in its final five games.

Modster could be easy to defend, but he could also provide a spark.

"Stay glued on your, man because he can throw it through a keyhole," Shelley said when asked about his mindset. "Stay glued on your man, that's definitely something that you have to do, because a little bit of space can get a completion on you. You definitely have to be on your game at all times."