2. Yonny Hernandez
The construction of the 40-man roster really is an art that MLB teams have to learn how to master. There are the obvious members of the 40-man, then there are the AAA replacement-level players that have to bounce up and down when there is a need (looking at you, Edwin Rios).
Then there are the prospects that could come up to help in the case of an injury (think Ryan Pepiot). To wrap it up, there are the younger prospects who are not quite big-league ready, but need to be protected in the Rule 5 Draft (this year being Diego Cartaya and Jonny DeLuca).
Every once in a while, there's a player on the 40-man roster who simply does not make a lot of sense. This year, that player for the Dodgers is Yonny Hernandez. Never heard of Mr. Hernandez? I don't blame you. It's not like he was a highly-touted prospect coming up through the Dodgers system.
Hernandez is a switch-hitting infielder who has very limited big-league experience. He has played 55 combined games for the Texas Rangers and Arizona Diamondbacks and is sporting a .198 batting average and .521 OPS.
He was never considered to be a top prospect and his minor-league numbers aren't great either. Hernandez has played 531 games in the minors and has a .712 OPS with five home runs. The one thing Hernandez brings is speed, but everything else is so poor it's hard to justify his spot on the 40-man.