​The No. 1 pick across almost all the mock drafts could be wrong. The ​Arizona Cardinals are possibly looking at a defensive upgrade over taking another shot at quarterback with their top pick.

Bob McManaman of the Arizona Republic believes the Cardinals will select ​Nick Bosa with the first pick if they aren't able to trade down.

The ideal scenario for the Cardinals is a trade down as teams like the Raiders and Giants could be hungry for a QB prospect like ​Kyler Murray. ​​The Raiders recently acquired Antonio Brown as an offensive weapon and held a private workout with Murray. Meanwhile the Giants cannot continue with a thoroughly washed up Eli Manning at the helm. 

With not many top quarterback prospects in this draft, both teams could be jumping at the opportunity to grab Murray. However, trading up to the top is costly, and it's possible no team makes an offer that excites the Cardinals. 

Bosa would still be a very productive pick for the Cardinals. The defensive end dealt with an injury in his last season, but is still considered one of the top defensive prospects in his draft class. Bosa's combination of quickness and power makes him a dangerous player as a pass rusher. 

Selecting a DE as talented as Bosa isn't a bad backup plan for the Cardinals.