Obviously they have bigger issues than their fantasy ratings, but I’m curious if their fantasy ratings are of any interest to them.
I know many do play FF.
Quite a few players tweet about fantasy rankings so I assume they care about their own. You know what they say about assuming though.
I remember an anectdote about Chris Cooley scoring like 3 TDs one day, and being super excited, because he had himself on his fantasy team.
Other than that - there are tons of players who get pissed off about fantasy sports. Peyton Manning has been heard dismissing someone complaining to him for sitting in the final few weeks of the regular season (fantasy playoffs).
It’s even more pronounced in baseball. There are so many old-school guys in baseball that think any sort of stat keeping is anathema to the sport, that they really look with disdain on the hobby. Sam Walker’s “Fantasyland” is a great read - he’s a WSJ writer who gets into an elite fantasy league, and focuses on drafting guys he knows, or knows he can get near in the clubhouse as part of his job so he can give them extra encouragement. At one point he lobbied outside the hotel Billy Beane was staying in so his guy could get more playing time - Billy Beane was…not pleased.
Maurice Jones-Drew is actually writing fantasy columns for SI.com now.
Matthew Berry always likes to tell the story about when Matt Hasselbeck was playing fantasy, had himself and Favre on his team, threw four TDs in a game that week, and had himself benched for Favre.
I recall an incident a year or so ago where, late in the game and up by a point or two, the Jets schemed to let MJD score in the hopes of getting the ball back with enough time to make a drive, but he smartly took a knee inside the one yard line, allowing the Jags to run down the clock and kick a game winning field goal as time expired. He later apologized to his fantasy owners.
A better story I heard was a QB (I think it was Hasselback) having a monster game – something like 4 TDs and gobs of passing yards – while sitting on his own FF bench.
Ouch.
I’m going to go out on a limb and guess he started Favre instead. 
Of course, fantasy statistics have at least some correlation with performance on the field, and they do want to perform well on the field.
Related question: do players care about their ratings in Madden? The answer is an unequivocal yes, at least for wide receivers and running backs.
There was a great Outside the Lines a few years ago about gaming among athletes. Some coaches liked the fact that teammates spent time with each other, others disliked the tendency for inappropriately late nights at crucial times. One thing they pointed out was it often gave young rookies something to do when they were on a road trip and not old enough to hit the bars with teammates.
I don’t think there’s ever been an NFL rookie under 21…
Amobi Okoye was barely 20 when he suited up in Week 1 of 2007.
But there have been plenty of Hockey, Baseball, and Basketball rookies that have been.
He was playing against Cooley in his fantasy matchup that week. That’s what made it a story. (“Did it ever cross your mind?” “Yes, but I didn’t care a whit.”)
This. I listen to a lot of sports talk radio and rarely hear players comment on fantasy football. Apparently, everyone knows about their Madden ratings, though.
A few years ago, one of the Steelers caught a lot of flack over Madden. The player was portrayed as white in the game, and is black. Leading another player to exclaim “Man, they messed up his paint job!” It was hilarious.