Which is why, if a big-bodied WR or, preferably, a stud TE became available, I'd make that move NOW. Allen is right on the cusp - but you can tell that he's chasing a bit, in part because he feels he needs to win games himself, in part because he doesn't have someone he can rely on to get open on every single play. (Side note, Beasley, who is the closest thing to a security blanket, was double- and triple-covered on third downs yesterday.) The tight ends on the roster have taken turns dropping critical passes all season, including Knox whom I love but who looks to be a year away from being a consistent contributor.
Go get him a Kyle Rudolph type and watch him relax a bit, then you'll see growth.