The primary culprit in the Tigers' running game not being where head coach Gene Chizik wanted it to be was poor technique, poor steps and poor pulling angles, said Grimes, who is starting his fourth season as Auburn's offensive line coach.
"I don't think it was a lack of knowledge of who to block," Grimes said. "I don't think it was a lack of effort. I think it was a lack of focus on their fundamentals, which will get better."
Another factor in the offensive line's sub-par performance was fatigue from taking multiple reps in a row for the first time this spring, noted Grimes.
"You know the quote, ‘Fatigue makes cowards of us all,' and that was certainly evident on Saturday," he said.
"Neither of them played very well, but it wasn't just them--it was us collectively," said Grimes after Monday' practice. "But again, if you went back and looked at what they had done the couple previous days, they were making progress."
Christian Westerman will be a redshirt freshman this fall.
Grimes said the challenge for the offensive linemen is to continue to improve and play the way they practice when it is time to scrimmage.
The Tigers were short-handed for Saturday's scrimmage as first-team left tackle Greg Robinson returned home to deal with family issues. True freshman and January enrollee Patrick Miller stepped in for Robinson.
"Typically, you get a true freshman in there taking a lot of reps and you notice him every play," said Grimes. "It wasn't that way. We were able to run our offense with him in there taking a ton of reps.
"The kid, he's got a long way to go in terms of understanding how to play the game, but he's got a great amount of want-to, and his eagerness to learn and his mental toughness will give him a chance to be a great player," added Grimes.
Patrick Miller arrived at Auburn in January after graduating early from high school.
With installing and learning new offensive coordinator Scot Loeffler's system the primary task at hand this spring, Grimes said that moving guys around to find the best five can wait until fall camp.
"Right now, you've got to give the guys the chance to learn, especially with a new offense," the coach said. "So if I'm moving guys around too much right now, it becomes counter-productive. They don't have a chance to learn the offense. They don't have a chance to really show what they can do at their best."
With the offensive line short-handed this spring, one thing that has Grimes excited about fall camp is the competition that will generated by the five true freshmen offensive linemen who will arrive on campus this summer.
"When we get our guys in this fall, we'll have by far the most competition that we've ever had since I've been here, and we need that," he said. "It's a good thing for Auburn when guys have to really earn the right to be on the field rather than just being one of the best five who's here."