As Auburn prepared for the start of spring practice last month, new offensive line coach J.B. Grimes pored through hours of film, reviewing the performance of the Tigers' offensive line as a whole, and particularly each of his returning players from last season.

When Grimes got through with it, he met with the offensive line and gave his players an earnest review of their 2017 performance.

"He was like, 'OK, this is what we were terrible at, and this is what we need to get better at,'" guard Mike Horton said.

So what was the most glaring critique Grimes had of the line? According to Horton, it was all in the details.

"Coach Grimes really loves details," Horton said. "He focuses on that and he felt like we weren't really detail-oriented last year."

Grimes, who returned to Auburn as offensive line coach following two years away from the program, has made that his primary focus this spring as he replaces the man who once replaced him, Herb Hand, and tries to identify the Tigers' five-man starting unit for next season.

Grimes is different than Hand in many aspects, including stature and personality. Their biggest difference when it comes to coaching, however, lies in the details.

"Coach Grimes is bringing a whole new aspect to the game," defensive tackle Derrick Brown said. "He definitely is just a completely different person than Coach Hand."

As Horton said, Grimes is very focused on teaching the fine points of playing offensive line, nailing down the details of technique and footwork in both run blocking and pass protection. Grimes wants his offensive linemen to be the masters of their position, each one focusing on one primary role this spring.

Hand, on the other hand, enjoyed teaching versatility in his line. Players cross-trained at multiple positions -- which paid dividends for the Tigers last season when Austin Golson started at four different positions and played all five -- so that many could be plugged in at various holes and still know and execute the scheme..

"(Grimes) focuses on details extremely well, so we focus on details and then we worry about scheme later," Horton said. "Spring is just a time to grow and get better."

Auburn coach Gus Malzahn said the two assistants, both of whom worked with him at other schools prior to reuniting on the Plains, also use "some different terminologies" when teaching the position.

"J.B. has his own brand of terminology," Malzahn said. "The older guys, some of the older guys were actually here with him. It is just a matter of the guys getting used to his approach, his terminology. Some of the techniques are a little bit different. The guys have responded very well. I feel real good about -- I have said this before. J.B. is one of the better teachers, just true teachers, that I have had in 28 or 29 years of coaching. He is a true teacher."

That's where Grimes' transition back to Auburn should be easier, as several of the Tigers' offensive linemen were previously coached by him when he was with the program in 2015, including Horton, center Kaleb Kim and guard Marquel Harrell -- all of whom are expected to start in 2018.

"Since he already coached me I know what to expect from him so it hasn't really been a weird transition for me," Horton said. "Maybe for some of the other guys, but for me and Marquel, we already know him. Bailey (Sharp) and Tyler Carr, they came in early, so they already know him, too. For us it's not really a transition."

Those veterans know what to expect from Grimes, as well as how he operates and what he demands from his linemen. Horton said Grimes is the "same old guy" he was when he last coached at Auburn -- a thorough teacher who enjoys cracking jokes and keeping his guys loose before they take the field -- and all of the veterans were glad when they found out he was returning.

'I ain't going to lie to you; I didn't think I was going to see him again," Horton said, "but it's good to have him back."

Tom Green is an Auburn beat reporter for Alabama Media Group. Follow him on Twitter @Tomas_Verde.