Sano has over 6 years of service, he can't be optioned without his consent. The Twins can send him on rehab for 20 day maximum. When he exhausts his rehab time, the Twins will have to activate him or DFA him. If he looks good for the rehab, it is a no-brainer to activate him, but if he's struggling with minor league pitching, I suppose they will look at at DFA or trade for little value.