How mad? Enough to ask to be taken off the game.
Fournette jokingly (we think) asked EA Sports' Twitter feed to remove him from the game after receiving an 87 rating this season:
Fournette previously retweeted a video of his upset reaction upon hearing his Madden rating, after which the game's Twitter account responded with a form letter asking him to provide evidence he deserves a higher score:
The Jacksonville Jaguars running back rushed for 1,040 yards and nine touchdowns during his rookie season. There are nine running backs in the game with higher ratings; Fournette is tied with LeGarrette Blount, Dion Lewis and Christian McCaffrey for 10th place at his position.
Most of that likely comes down to the fact Fournette did not do much as a pass catcher during his rookie campaign and averaged a relatively mediocre 3.9 yards per carry.
As for whether he could actually pull himself out of the game? Nope. EA Sports licenses player likenesses through the NFLPA, of which Fournette is a member. Fournette would have to pull himself from the union altogether to actually get himself removed.