I wouldn't expect 3 rookies starting for a 13-3 team unless something drastic happened.
It's possible, I suppose. If you got Campbell at MLB, a WR #2, and a RT. But I seriously doubt a WR or RT will come in and start day 1 unless they are 1st rounders, and we aren't getting 3 players good enough at those positions to start day one over what we already have.