It looks like the Cowboys will leave no stone unturned to find a developmental quarterback this season, particularly since they've have done nothing to address their backup QB position so far this offseason.

Mike Garafolo of FOX Sports reports that the Cowboys held a private workout for Penn State quarterback Christian Hackenberg yesterday.

Cowboys held a private workout for Penn St QB Christian Hackenberg yesterday. They're looking for a developmental QB. He needs to develop. — Mike Garafolo (@MikeGarafolo) March 31, 2016

Hackenberg started out strong in college, but then regressed in his sophomore and junior seasons. There's been a lot of speculation, including speculation from Hackenberg himself, why this happened, but Garofolo is right when he writes that Hackenberg still needs to develop before he can play in the NFL.

Here's our own DannyPhantom with a summary of Hackenberg:

The Nittany Lions junior was once thought to be a future star in the NFL. He was highly coveted coming out of high school and tore it up his freshman year at Penn State. Of course, the scenery was real nice for him that year. He had a star receiver, Allen Robinson, to catch the ball and was coached by Bill O'Brian. He set a school record as he threw for 2,955 yards that season. But then O'Brian left to become the head coach of the Houston Texans and Robinson was drafted by the Jacksonville Jaguars. Hackenberg and the Penn State offense would regress. There were times that he struggled with his accuracy and would panic in the pocket. Penn State's offensive line was terrible so Hackenberg was a sitting duck. While the flashy stats would fizzle, the skills are still there. Hackenberg has great size and arm strength. He can throw the ball deep and puts a lot of oomph on his passes. Despite the frenzy in the pocket, he has really good footwork and can use his legs to get out of trouble. And he's got the size to handle the abuse of the NFL.

Hackenberg is the sixth quarterback the Cowboys have worked out or will work out this offseason, as the pre-draft visit tracker at the bottom of this post shows. Arguably, outside of Jared Goff, all the QBs on that list still need to develop before they're NFL-ready, so needing time to develop is not necessarily a knock on Hackenberg.

But it does highlight one particular point of the Cowboys' QB search. Unless they get Goff, whichever rookie QB they bring in will very likely sit behind Kellen Moore on the depth chart, as none of these rookies would be ready to play (and win) immediately if Tony Romo gets hurt again. Which means that in terms of backup QB in Dallas, Kellen Moore is it, barring a move for another veteran between now and the start of the season.

For now, we know the Cowboys are taking a close look at what are arguably the top six QBs in the draft, and it wouldn't surprise us one little bit if we were to add more names to this list shortly.

The visit tracker separates players by the type of visit they had or will have with the Cowboys (Go here for details on what each visit type means).