Reaction to developments on the field, and off … 1. Big week for the South We’re being a bit loose with the timeframe. The first in a series of events that will shape the division unfolded on Jan. 6, over a week ago. That’s when Utah tailback Tavion Thomas announced his return for next season, a modest surprise that instantly solidified the Utes as the division frontrunner. Our timeframe includes a series of notable developments in Westwood, where UCLA quarterback Dorian Thompson-Robinson and tailback Zach Charbonnet announced they would return for ’22; where defensive coordinator Jerry Azzinaro is expected to resign (per published reports); and where coach Chip Kelly agreed to a contract extension. The return of two key playmakers, the chance to revamp the defensive leadership and the stability at the top of the org chart all improve UCLA’s prospects for next season. Our timeframe also includes the news that former Washington State quarterback Jayden de Laura has transferred to Arizona, where the Pac-12’s Offensive Freshman of the Year will compete for the starting job and, most likely, supercharge Arizona’s efficiency at the most important position. (If de Laura doesn’t win the starting job, then one of the returnees will have outplayed him — and that’s also good news for the Wildcats.) The division’s big week ended Saturday when Mario Williams, one of the best young receivers in the country, announced he was transferring from Oklahoma to USC. For all the help Williams will provide on the field in the fall, his immediate contribution takes the form of buzz: Other potential transfers assuredly will give more thought to joining USC now that Williams has done it. Former Sooners quarterback Caleb Williams sits atop that list but is hardly the only elite talent likely to give the Trojans strong consideration in the wake of Mario Williams’ decision.