While we are always excited to see players gain eligibility at a new position as fantasy owners, players that are expected to lose eligibility are often overlooked as owners start maneuvering their roster for optimal keepers. There are a number of players whose value will take a hit based on that fact, so let's look at a few of them. Note that there is the possibility that some of these players will reach the 20 game threshold before the end of the season.
Players Where the Flexibility Was Nice
Each of these players are already considered in the top 10 at their main position, but were nice enough to give their owners the flexibility of playing them somewhere else when an opportunity presented itself.
Third Base - Miguel Cabrera,
Cabrera has appeared in 10 games (8 starts) at third this year, so he may hold onto the eligibility in some formats. It's not like his value changes particularly as a result of losing the eligibility.
Shortstop - Dee Gordon
Gordon started the season qualified only at shortstop, and while playing second base all year, has not even appeared once at his original position. He's been a top 5 option at both positions, and there's every reason to think he can repeat that level of production in 2015 as a second-base only option.
Second Base - Josh Harrison
Harrison has appeared in 16 games at second base this year, with 13 starts, so it's possible he will retain eligibility there depending on whether your league uses 20 games or 10 starts as a threshold. Harrison will still be eligible at both third base and in the outfield, and should be a top 10 option at third for next year.
Players Who Lose A Ton Of Value
Catcher - Joe Mauer, Carlos Santana
We knew that Mauer was going to lose his catcher eligibilty with the permanent move to first, and while Mauer still has a lot of value at first base, it clearly moves him out of the top 50 overall for most formats. Santana may or may not qualify at catcher in your league next year, as he has made 9 starts and 10 total appearances behind the plate this year. He does have third base eligibility, but he's not likely to be a top 15 option at the position to start the year.
Second Base - Matt Carpenter
Carpenter's middle infield eligibility was expected to go away this year with the trade of David Freese, and while he has had a solid season, his performance would play better at second base going forward for fantasy purposes.
Players Outside the Top Ten At Their Position Where the Value Was Nice To Have
Second Base - Jed Lowrie, Dustin Ackley
Lowrie still qualifies at shortstop, which is the position where his value can really shine, but there is a decent chance that he ends up playing some second base wherever the 2015 season finds him. Ackley has been hitting better this year than in previous, but his value as an outfielder only is drastically different than when it includes second base.
Outfield - Nick Castellanos
Castellanos came into the season with outfield eligibility in a number of leagues as a result of playing the position in the minors in 2013, but has only played third base for the Tigers. I think Castellanos' value isn't affected too much, as he's a better option at third base than he was in the outfield anyway.