Every rookie has a learning curve once he hits the NFL, even top 10 draft picks like Devin Bush. I've gone over why Bush was a top priority in the draft and why he's the centerpiece for the future of the Steelers' defense. His upside brings several positives, but there are always elements of a player's game to polish.
Bush's area to grow in is working against blockers at the point of attack. It's a huge part of his game that'll be tested by NFL rushing offenses.