Even prior to last season’s controversial, at-the-buzzer call that took away an upset victory for Colorado at Arizona, it felt like the Wildcats were on the verge of becoming CU’s top Pac-12 rival for men’s basketball. Since Colorado joined the conference, the teams have met six times, with each team winning three. Colorado coach Tad Boyle agrees about CU vs. Arizona becoming a developing rivalry. The teams meet again Thursday night (7 p.m., ESPN2) in UA’s McKale Center. “I think so, just because of the (closely contested) games,” Boyle said of the budding rivalry vs. Arizona. “We’ve played them tough. They’ve been great games, fun games to watch. “I don’t know if Arizona considers Colorado a rival,” Boyle added. “But I know our guys enjoy playing against them. And I respect their program. (Arizona’s) Sean Miller is a heck of a coach. I don’t know if there is one rival for us, but Arizona has become a fun game.” The average margin of victory in those six meetings has been 8.3 points. But that’s deceiving because Arizona ultimately won last year’s controversial game in overtime by nine points over a disheartened Buffs team that thought it was robbed of a huge victory. An apparent, last-second game-winning 3-pointer by CU guard Sabatino Chen was disallowed by officials after they examined a video replay. Still photos appeared to indicate that the basketball had left Chen’s hand before the game clock showed that time had expired.