The coaching staff is not doing him any favors either, the WRs seems to be running routes that are 10+ yards downfield. Thats all well in good we have the QB that can theoretically throw a vertical passing game but why not work to our strengths (lack of OL time/good hands WR)?
McCoy, Charles, Ray Ray etc should all be running short screens, slants, crossing patterns to get the ball out quick to get Allen in a rhythm early and move the ball at least into field goal range.
Then when we are in 2nd and 3 or less we can try to hit those 20 yard + downfield throws.