Cal Ripken weighed 220 pounds when most other SS weighed 175 soaking wet (I think Ozzie Guillen was listed at 150!). Ripken ushered in a new era of large shortstops (A-Rod, Jeter, etc.) that could play their positions very well in spite of their large size and did not seem overly prone to injury because of their size (particularly true in Ripken's case). Mike Trout (235 pounds) and Jason Heyward (245 pounds) are both exemplars of modern-day large outfielders that play their positions very well and don't have reputations as being injury prone. Based on these and other examples I don't believe that simply due to his size that Sano cannot become an absolutely adequate defensive outfielder. In terms of experience, we don't have to look past Danny Santana in 2014. Prior to 2014 he had only played a handful of minor league games in the outfield, but when given the opportunity to play CF he was not an embarrassment in the field and his fWAR was 3+ (largely because of his offensive success that year). While Sano certainly doesn't have Santana's range, he does have a strong, accurate arm that should dissuade baserunners from taking extra bases and if he works hard with the coaching staff he should be able to develop enough outfield skills to at least make the routine plays and keep the balls in front of him. If he does not work hard (and I have no reason to believe he won't) he will not be very good; but, this is true even if he plays 3B or DH -- if he isn't willing to work hard, keep his weight in check so his athleticism can shine though, and refine his skills, he will quickly become an overweight has-been that wasted an opportunity to be a once-in-a-lifetime type player.