I understand the sentiment, after all, if you thought Polanco lost magical development time because he was playing second base from April-June last year, than they same theory might hold true to Santana. The problem, I think, is that Santana wasn't really seen as much more than a UI type player with speed. That's not a bad thing, UI are needed and positional versatility only improves that. I think the bigger concern with Santana is that he hasn't shown much ability to play strong defense at any position or to hit with limited playing time. My guess is that if he had steady playing time his offensive numbers would be a bit better than they've been the last two years - maybe he could produce a 85-90 OPS+ if it all broke right - but his defense has been pretty shabby. I'd rather take a chance with Polanco and Escobar at short and see if we can find a UI that fits a bit better. But I'd also like to be proven wrong and see Santana return to his rookie glory.