I'm not even saying Redman is the answer. But he has shown the ability to be the answer where others have shown not to be. And I don't think it would take alot of reshuffling to find out.
It could be as simple as they felt that Redman would make it the practice squad and Summers wouldn't. Maybe someone was already sniffing for Summers. So if they want to keep both, they try sending Redman down. One thing is known; we can't house both of them right now.
BUT if Parker goes FA, then Mendi moves up and we need another back. Also to, maybe Summers proves to be a flop or a success as the season progresses. Who knows what this season holds. Maybe we have 2 openings in the RB corp next season.