Best surprise, hitter: Daniel Nava
Presumably few outside of perhaps Nava's extended family expected to see him in the majors this season, at least with the Red Sox, an organization that didn't even deign to invite the 29-year-old outfielder to big-league camp this spring. But the relentless injuries to various outfielders ahead of him on the depth chart gave him an opportunity, and did he ever take advantage of it. He had a .900 OPS in May, essentially duplicated the performance with an .892 OPS in June, and while he's cooled off lately, he's still hitting .275 with a .388 on-base percentage. He's proven he belongs in the big leagues.