Is Ryan Day’s biggest concern turning into one of No. 1 Ohio State’s strengths?

When Isaiah West arrived at Ohio State last year, he wasn’t yet cleared for full football activity.

The three-star running back recruit from St. Joe’s Prep in Philadelphia suffered a knee injury in his senior year of high school that kept him out until late in preseason camp. But as he was rehabbing and adjusting to his new home, a message from associate strength coach Kenny Parker stuck out. He told him he might be rehabbing one knee, but he had another one he could train.

“You have to over-train the other side,” West said.

West lived by that message this offseason again, as the sophomore rehabbed from shoulder surgery. Fresh off a promising freshman year in which he gained 310 yards and two touchdowns, West lived in the weight room doing workouts on his good arm. When he was cleared, he worked to even things out on the other side.

The extra work paid off because he said he added 12 pounds of muscle. Though he’s going into this season at 220 pounds, he feels faster and more explosive.

“He had a tremendous offseason — one of the best in the whole building,” Ohio State coach Ryan Day said. “When you have the injury like he had, sometimes it takes a year or two to get back into it. We’re seeing him look the best physically he’s looked, so that’s exciting.”

Ohio State has not been shy about pushing the running backs to raise their expectations this offseason, even after West and fellow sophomore Bo Jackson, who led the team with 1,090 yards last year, missed the spring.

Still, the top-ranked Buckeyes entered camp with a lot of uncertainty at running back — enough that Day said the group was his biggest concern at Big Ten media days.

The Buckeyes may be preseason No. 1 in the AP poll for the first time since 2015, but that doesn’t mean much to their eighth-year head coach if he can’t get real growth from the second-year duo, along with newcomers that include Florida transfer Ja’Kobi Jackson and freshman Legend Bey.

“We got these pieces, but if we’re going to get where we need to go, we need a high level of play from that position,” Day said in Chicago. “Here’s where you have to take that next step. We’ve had guys in the program that had a very good freshman year, and I’m not going to say sophomore slump, but it was OK, and then the third year they turned it on. We can’t afford to do that. This has to be a huge year for those guys.”

Through two weeks of camp, it sounds like everything the Buckeyes did in the offseason, despite injuries, is paying off as they seek to improve areas of weakness. Most notably, breaking off explosive runs.

The Buckeyes were 45th nationally in percentage of runs of at least 12 yards last year, per TruMedia, which isn’t bad considering the lead backs were freshmen. But there was a massive drop beyond that, as Ohio State running backs finished 92nd with just 2.8 percent of runs going for at least 20 yards.

There’s a lot that goes into that stat. Having a quarterback with limited mobility takes away a threat defenses need to account for. Inconsistent offensive line play also factor into the equation. But the lack of explosive plays is something West and Jackson — the Buckeyes’ only returning running backs who carried the ball last year — took to heart.

It started in the weight room, where they rehabbed shoulder surgeries and worked out together. But there’s only so much that lifting can accomplish when a new offensive coordinator, Arthur Smith, is coming in to change the scheme. They couldn’t practice how to get to the second level, though they could memorize how Smith wanted them to run wide zone, inside zone and where the gaps would be against various defensive fronts.

“We have a structured plan for the offense,” West said. “We don’t have 1,000 different plays. We have a few that we’re really good at, and Arthur Smith is really big on being brilliant in the basics.”

As they dived into the offense, it became clear that the rushing attack could benefit from Smith’s plan. Jackson, in particular, was excited about the wide zone aspect.

“It’s a great offense,” Jackson said. “He uses the tight ends a lot, a lot of single-back formations and moving the tight ends around.”

That works into the strength of Ohio State’s roster, with the versatility it has at tight end, and it will allow the running backs to get into more space.

However, there’s no substitute for on-field reps.

Right away this summer, West, who was with the starters early on, felt the benefit of the work he put in the last two years to recover from both knee and shoulder injuries. Jackson, a 1,000-yard rusher as a freshman, has come on strong, too, drawing strong reviews from Day after Saturday’s scrimmage.

“He’s done a much better job at the second level,” Day said. “We talked about it: You either run over or run around them, making them miss, and you’re seeing that. It’s showing up on film, and it did not show up on film last year.”

That’s a strong statement from Day, who has said in past years that it can be hard to evaluate running backs in camp because they aren’t facing full contact. West said that has not been the case this year.

“Running backs are always live,” West said with a smirk.

At least some contact has given everybody a full look at what Ohio State is running, and the reviews have been good.

“Y’all don’t even know how much better Bo Jackson has got,” West said. “You can see he’s decisive, hitting it with speed, making people miss. We going to be good.”

What about the freshman, Bey?

“If he continues to grow and continues to get better, all of those things, takes care of the football, you can see what a weapon he can become for us,” Day said.

There’s a strong belief at Ohio State that this year’s running back group is deeper than it was a year ago. Whether that will translate to the games remains unknown. It’s why Day is still pushing them for more, with so much of the outside focus on the passing combination of Heisman finalist quarterback Julian Sayin and All-American receiver Jeremiah Smith.

“I’m excited about the room,” Day said. “Not where we need to be, we still have a couple weeks to get there, but it’s good to have a group that has experience.”

It’s been clear so far that the work the running backs did this offseason to recover from their injuries is paying off.

If it shows up Sept. 12 against Texas, the sky may be the limit for the top-ranked Buckeyes.