The first of a trio of Top-25 matchups during the opening weekend in college football is arguably the most marquee with No. 1 Georgia vs. No. 14 Clemson from Atlanta. Ahead of that early game which he’ll be calling on Saturday, Greg McElroy previewed the keys to it between the Bulldogs and Tigers on ‘Get Up’ on Thursday. That started with Phil Mafah as Clemson’s lead back now. He should be a key versus a defense that was slightly worse against the rush last fall than they’ve been. CLICK HERE to go to PrizePicks and use code ON3 to receive a guaranteed $50 once you play $5 in lineups! “I look a…