You never know. Depends on the croatia-cameroon game. if croatia loses, they'll have little incentive.
Anything can happen of course, but Brazil have played the 2 toughest teams in the group, and only the weakest remains. Cameroon looked terrible vs Mexico.
Whereas Mexico still have to face a very tough Croatian team potentially either needing points, or playing for pride.
Either way, 2nd place in group A looks like it would avoid Spain as it stands, even after the 5-1 defeat, no one wants to play Spain in the second round.