Ohio State officially kicked off its spring practice on Tuesday, and Urban Meyer set out on the enormous task of replacing the 16 starters he lost from last year's team.
The Buckeyes, fresh off a 12-1 2015 campaign that actually fell short of their enormous expectations, will look completely different this fall without superstars Ezekiel Elliott, Joey Bosa and Darron Lee suiting up for the Scarlet and Gray.
With so many holes to fill before kicking off the 2016 season against Bowling Green this September, Meyer is anticipating more competition than he's seen during his 15-year head coaching career.
"This is uncharted waters for me," Meyer said, according to Eric Seger of Eleven Warriors.
While the depth chart won't be finalized until fall camp, here are the most important position battles that will take place in spring practice.
Ezekiel Elliott was the driving force during Ohio State's historic run through the 2014 postseason, and he was the only consistent presence in an offense that failed to establish an identity in 2015.
With Elliott's departure to the NFL, the Buckeyes need to figure out what to do in a backfield that's fortunate enough to return J.T. Barrett at quarterback.
Over the last four seasons, the Buckeyes have identified lead backs and leaned on them heavily. From 2012-13, that role was filled by Carlos Hyde, who rumbled his way to 2,689 total yards and 35 touchdowns. Over the last two years, Elliott amassed 4,125 yards and 41 touchdowns.
But Meyer hinted on Tuesday that it could be a running-back-by-committee approach this fall.
“As I see it right now, you’ve got four guys carrying the ball for us in the fall,” Meyer said, via Tim Shoemaker of Eleven Warriors. “The two running backs and then Dontre and Curtis.”
The two running backs he referenced—Mike Weber and Bri'onte Dunn—will get long looks this spring. Both are in the bruising, bulldozing mold of Hyde, and they'll bring the physical edge back to Ohio State's running game.
Dontre Wilson and Curtis Samuel, who will rotate in from the H-back spot, will provide the change of pace from the perimeter.
Weber, who surged in fall camp last year before a knee injury derailed his progress, has a great opportunity to continue the legacy left by Hyde and Elliott.
The wide receiver unit is undergoing a complete overhaul after starters Michael Thomas and Jalin Marshall defected to the NFL early and Braxton Miller graduated.
That mass exodus has left the Buckeyes completely void of experience on the perimeter, as Samuel, Corey Smith and Noah Brown are all set to return in 2016. Those three will all be held out or limited in spring practice, though, as they're rehabbing from various injuries, per Doug Lesmerises of Cleveland.com.
Those injuries will open up huge opportunities for some of the younger guys in the unit. Redshirt freshman Torrance Gibson and true freshman Austin Mack, who graduated high school early to participate in spring drills, will be in the mix to fill Thomas' vacated spot.
But without three key contributors, Ohio State won't be able to solidify its perimeter attack until the fall.
"Guys we're really counting on that can't go because of injury, we have a lot of work to do," Meyer said on Tuesday, via Lesmerises. "That's the thing that kicks you in the teeth."
The safety position is facing the same obstacle as wide receiver after juniors Tyvis Powell and Vonn Bell burned their final year of eligibility to make an early jump to the NFL.
The pair served as anchors in Ohio State's pass defense over the last two years. After the secondary bottomed out in 2013, Powell and Bell took over and fueled a turnaround in 2014. Last season, they were the last line of defense in a pass defense that ranked 16th nationally.
Erick Smith and Cam Burrows should factor into the mix this fall, but both were limited to open spring practice, per Lesmerises.
That opened the door for a pair of underclassmen who looked good on the first day of camp, according to Scout.com's James Grega Jr.:
With Ohio State needing to find another corner to start opposite Gareon Conley this fall, the defense really needs a solid pair of safeties to tighten up the secondary.
All recruiting rankings and information courtesy of 247Sports.
David Regimbal is the lead Ohio State football writer for Bleacher Report. Follow him on Twitter @davidreg412.