has Desmond shown that he's improved a TON at SS in the time he's been there?
Guzman and Desmond have put up literally the exact same numbers in the minors and Guzman went on to have a decent defensive career. Look at Hanley Ramirez, he was horrible and improved with time. Just give Desmond some time and he will improve the same way almost all Major League SS do.
Fielding %:
Desmond: .936
Guzman: .937
Range Factor:
Desmond: 4.40
Guzman: 4.39
Double plays per 162 games:
Desmond: 99.8
Guzman: 99.1