Ted Miller Colorado gets an early -- and chilly? -- start to spring practices Monday, leading the Pac-12 out of the gate.Not to be caught off guard, here are five major issues confronting the North Division as spring practices begin.Here's what we had to say about the South.1. Oregon post-Mariota: The Ducks are not only replacing their quarterback, they are replacing the best player in program history. Heck, Marcus Mariota, the 2014 Heisman Trophy winner, is one of the greatest players in Pac-12 history. Originally posted by ESPN.com - Pac-12 Blog Click here to view the article.