Oakland's biggest mystery in 2008 was rookie first baseman Daric Barton, who had hit at every level until last year and who had reached base in every game he played as a September call-up in 2007. Barton had a dismal season, batting under .220 much of the way before finishing at .226. And while two other youngsters, outfielders Travis Buck and Carlos Gonzalez, were sent down when they struggled, Barton was left to sink or swim at the big-league level all season.