Before Tosh Lupoi's promotion became official, one former Alabama staffer expressed doubt when told Lupoi was set to take over as the Crimson Tide's defensive coordinator.

"I don't see that happening," the coach said at the time.

There were questions about Lupoi's ability to be a high-level defensive coordinator then and now as Lupoi is less than two weeks away from his Alabama DC debut.

Could he end up evolving into a very good coordinator? Absolutely. But he's unlike any previous Nick Saban defensive coordinator, which is why there are still doubts surrounding Lupoi's promotion.

Dating back to Saban's first head coaching job at Toledo in 1990, all of his previous defensive coordinators had prior experience as a defensive backs coach, defensive coordinator and/or head coach.

Many of them have been, like Saban, considered DB guys, including the previous two Alabama defensive coordinators. More importantly, though, Saban has typically wanted his defensive coordinator to have a great understanding of each level of the defense -- from the front to the secondary.

Lupoi is admittedly still a work in progress with that.

While the 37-year old is known around the country as a top-notch recruiter and outside linebackers coach, the former defensive lineman has never coached defensive backs and is still getting comfortable with the nuances of the secondary.

"That was a major goal of mine of four seasons ago is to come here and to try to grow as much as possible and learn from the best in the business when it comes to the coverage concepts," said Lupoi, who joined the Alabama staff in 2014 after working as the defensive line coach at California and Washington. "So I think that process started when I came here to Alabama. Now, I've gained a lot of confidence in that. But, of course, I'm still getting better and learning it every single day."

There are other questions, too.

Jeremy Pruitt, who was Alabama's defensive coordinator the last two seasons before leaving for Tennessee, is known for being terrific at quickly recognizing what's going on and being able to adjust on the fly. Those who have worked around him feel like that's part of what made him such an excellent defensive coordinator. It's unlikely a first-time defensive coordinator like Lupoi will be at that same level.

"Doing it in a speedy manner (is the biggest challenge), I believe," Lupoi said. "You have to process the information quicker. ... You have to do it as fast as possible to get the guys in the best possible positions. Like anything, through repetition you get a little more confident and better (and) also understanding more so situational football and how we apply our defense. That's what this is for and spring ball and whatever it's been, the last seven or eight months, to make sure we can do that as best we can."

Saban does seem publicly pleased with Lupoi's progress. Coaches who have worked with Lupoi describe him as a very hard worker. And, according to Saban, Lupoi has invested a lot of time behind the scenes to prepare himself for this season.

It will help too that Lupoi has more talent to work with than most defensive coordinators around the country. It will also help having Saban and co-defensive coordinator Pete Golding, who helped UTSA rank fifth nationally in total defense last year.

Still, there will surely be growing pains especially given the Tide's early opponents. Week one: Bobby Petrino-led Louisville. Week two: Arkansas State, which ranked 10th nationally in total offense last season and returns preseason Sun Belt Conference player of the year Justice Hansen. Opponent No. 3 is Ole Miss, which ranked 18th nationally in total offense last year.

Not an easy start for a first-time play-caller.

"I think he's taken it upon himself to not want to be a guy that was viewed just as a recruiter or just as a guy that could coach the front," Saban said of Lupoi. "He's really, really committed himself to learning the big picture, the coverages, the secondary. I've spent a significant amount of time with him doing that and I think he's made a tremendous amount of improvement. Now, regardless of how much someone knows, when you've never been a coordinator before, it's a whole nother ball game to be able to implement it when the fur flies. We'll help him to do that."