That's what spring training and AAA is for. I'd rather Sands spent some time at AAA so that the Sox can see what he can do at that level outside of the PCL in a less hitter friendly environment before making any serious commitment to him on the big club.
That's the approach we should do with every prospect that is close to ML-ready. Instead of just handing them roster spots, it's better they are fighting for it. If a prospect is too good to get sent down, so be it.
That basically goes for Rubby, Sands and maybe even Kalish + Lavarnway.