The rookie wide receiver, who was selected in the first round of this year's Draft, has just 159 yards from the first six games of the season.
The exec anonymously told USA Today: "Little receivers don't work with inaccurate quarterbacks.
"You can get away with those guys if you have [Drew] Brees or [Tom] Brady. Of course, you can get away with a lot with those guys."
At 5'8", Austin is one of the smaller wide receivers in the league, while Bradford has completed less than 60% of his attempts so far in 2013.