I'm not worried just yet given that some people saw a MAN blocking run in leaked footage and expected the FB to abandon his job to block a blitzing linebacker as if it were a zone blocking play.
In other words, unless I know the person giving their impression actually knows something about real football, I'm not going to take their word until I see it for myself.
Although on the other hand in previous Madden's I've seen fullbacks fail in man blocking.