Mater Dei High School basketball coach Gary McKnight  last week told the Star’s Bruce Pascoe  that 6-8 senior wing Stanley Johnson is the best player he’s coached in 31 seasons at the Orange County, Calif., school. Wow. That is a recommendation like few others in college basketball. Johnson, who is on an unofficial visit to Arizona this weekend, and generally ranked as one of the top three high school players in the Class of 2014, is from a school that produced Top-25-type recruits Tom Lewis , LeRon Ellis , Miles Simon , Reggie Geary , Jamal Sampson , Cedric Bozeman and Travis Wear , to name a few. I would submit that McKnight’s most coveted player until now, on paper, was Schea Cotton , ranked No. 1 nationally while at Mater Dei. How’d he do? He failed to qualify at UCLA, played at Long Beach City College and was an average player at Alabama. He did not play in the NBA. Remember Josiah Turner  and Fendi Onobun ? You never know. … UA basketball coach Sean Miller  will spend the final weekend before training camp opens Sept. 27 to participate in a charity coaches’ clinic this week at Fairleigh Dickinson University in New Jersey. The clinic supports an effort to fund research into children’s seizures. Miller will join Marquette’s Buzz Williams  and Pitt’s Jamie Dixon , among others.