Yes. Not because I don't think he has the potential, just because most lower level prospects never pan out. Considering the level he is at and his atrocious walk rate, I wouldn't hold my breath on him ever being anything special.
While I love the idea of developing a system of ongoing winning with a pipeline of prospects, not all prospects need to be held onto for this approach to succeed. I think many here are just clinging unrealistically to Sanchez like he alone could save the future of this franchise, and that is ludicrous. Acquiring relatively young players with multiple years of control (or extensions) at team friendly contracts can accomplish similar results and buy time for other lower level prospects and draftees to move up the ranks. AA really f***ed things up last winter, but that being said, he can put this team on a better track starting this winter with some key moves geared both toward the now and future state of this franchise.
Also, I would much rather hold onto Stroman at this point, in fact, I would be extremely hesitant to deal him off. He may not be labelled with as high of a ceiling, but he is considered to be MLB ready at this point, pitching in the upper minors and with better success. He fits this teams timeline for the now and has long-term implications as well.