The first thing of note on Sellers is his size. As of now, he's listed at 5'10" 155 lbs. He can get away with the height, but how many players in the majors weigh 155 lbs? Last season was just his first full season, however, he will already be 21 entering next season. He made a ton of errors last season after being hyped as sure handed. He's a very good prospect with the background of baseball that the A's look for. He'll still need to add a ton of weight though before he's considered a real major league possibility.