Arizona’s improved defense will be tested in the quarterback-rich Pac-12, but the Wildcats will ease into conference play with a game at Stanford on Saturday in Palo Alto, Calif.Arizona (2-1) began the season by holding FCS Northern Arizona to three points and limited UTEP to a late touchdown in last week’s 31-10 victory. In between, the Wildcats lost 31-24 in overtime at Mississippi State in a game in which five turnovers repeatedly put the defense in bad spots.Arizona, which rebuilt its defensive front with transfers, including Georgia defensive tackle Bill Norton, is allowing 4.83 yards per play. Last season, it allowed 6.59 yards per play, emblematic of about a decade’s worth of substandard defense.”We’re now going to just assume we’re going to play with great effort,” Arizona coach Jedd Fisch said. “And then when you can become gap sound and fundamentally sound, that’s when you can really take that defense to the next level.”Arizona’s supposed strength, its offense, has been solid, especially when quarterback Jayden de Laura plays as he did against UTEP, committing no turnovers. He was responsible for six giveaways in the first two games. De Laura, able to scramble and extend plays, has passed for 912 yards and rushed for 124.”This league is full of really talented dual-threat quarterbacks,” first-year Stanford coach Troy Taylor said. “This week, we see it again. It’s very challenging.”Stanford (1-2, 0-1 Pac-12) appears to be the worst team in the league, falling 30-23 last week to FCS Sacramento State. The Cardinal began conference play by enduring a 56-10 beatdown against USC on Sept. 9.