The 6-foot-8, 230-pound Ashley suffered the season-ending injury early in Arizona's first loss of the season Feb. 1 at California. He was averaging 11.5 points and 5.8 rebounds in 22 games, all starts, for the Wildcats this season.
The former McDonald's All-American had been a key to Arizona's success. The Wildcats were unbeaten, winning 21 consecutive games prior to the setback against the Bears.
Ashley said earlier this month that he would return to the school.
"I wasn't 100 percent [about coming back] before the injury," Ashley told ESPN.com. "But I've thought about it, and there's a very, very, very strong chance I'll be back at the University of Arizona next year."
ESPN.com's Jeff Goodman contributed to this report.