Among the four first-year coaches in the Pac-12, Arizona’s Rich Rodriguez is given the best chance to succeed in his first season because he has a good, senior quarterback in Matt Scott.

But there are plenty of reasons for concern in Tucson. Most notably there are worries about a defense that was among the conference’s worst in 2011. The defense may be even worse this season if preseason scrimmages are any indication. Here are three scenarios for the UA.

Best-case scenario: Arena Football League scouts become staples at Arizona Stadium, running back Ka’Deem Carey explodes into the national conscience and coach Rich Rodriguez’s scheming takes such advantage of quarterback Matt Scott’s skills that the Wildcats overcome their defensive shortcomings and fans turn out in droves to watch the scoreboard explode. The only downside in the Wildcats’ 8-4 record is the lawsuit filed by the scorekeeper for chronic carpal tunnel syndrome.

Worst-case scenario: Arizona’s defense can’t stop anyone and the defensive line suffers the unthinkable indignity of lowering its sack total (10) from 2011. Matt Scott has his moments at QB, but never lives up to the preseason hype or fully grasps Rich Rodriguez’s offense. The 4-8 season ends the way things usually end in the Arizona-Arizona State rivalry: The favorite loses. Worse yet, the Wildcat loss secures a 6-6 record for ASU and a bowl game for Sun Devils coach Todd Graham in his first season.

Most likely scenario: After a brutal start in which the UA faces Oklahoma State, Oregon and Stanford in its first six games, the Wildcats secure a bowl game and a 6-6 record with a season-ending victory over Arizona State and former Rodriguez protégé, Graham. Arizona’s other victories come against Toledo, South Carolina State, Oregon State, Colorado and UCLA – hardly an impressive list – but it’s enough to fuel excitement for the future.

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