Sophomore running back Curtis Samuel (4) has practiced as an H-back and wide receiver during the Buckeyes’ spring practices.Credit: Mark Batke / Photo editorWith seven practices gone from the 15-practice spring slate, there are still plenty of questions surrounding the Ohio State football team.Coming off their eighth national title in program history last season, coach Urban Meyer’s Buckeyes are in the midst of a handful of position battles, including at quarterback. While some might call the decision between OSU’s three star quarterbacks a good problem to have, there are other question marks surrounding the Buckeyes that might pose a bigger problem.With the defending champs halfway to the annual Spring Game, here are five things we’ve learned so far.1. Curtis Samuel is going to be a focal point on offenseSamuel, a rising sophomore running back, hasn’t been quite that in spring practice. A rising sophomore? Yes, but a running back? Not so much.The Brooklyn native has been used in a variety of roles so far in practice, and it’s not because he’s a bad running back. Meyer is mainly trying to find a way to get Samuel on the field with junior running back Ezekiel Elliott set to take most of the carries.Before finishing third among Buckeyes last year with 383 rushing yards and six touchdowns on the ground, Samuel was recruited to Columbus as a hybrid player. In fact, ESPN’s recruiting service listed the Erasmus Hall High School product as an athlete rather than a running back.He has all of the ability the coaching staff could ask for and he’ll be ready to roll once the regular season comes around after getting plenty of reps all over the field during spring practice.2. Spring is the time for young players to shineThroughout March and the beginning of April, Meyer stressed the importance of watching how many reps players have had. Some Buckeyes — senior offensive lineman Taylor Decker being the main name — are even part of the 2,000-rep club.So with veterans like Decker spending a lot of time sitting out, Meyer has a chance to put some of his younger players through the gauntlet.In certain cases, that might weed out the players who aren’t quite ready. But it’s also an opportunity for young players who are expected to get extensive playing time next season — like sophomore linebackers Raekwon McMillan and Dante Booker — to shine.3. J.T. Barrett is ahead of scheduleIn many cases, it wouldn’t be particularly noteworthy when the quarterback who didn’t win the national title for his team was able to participate in 7-on-7 drills. But the redshirt-sophomore Barrett isn’t your average “backup.”In fact, Barrett isn’t a backup at all, as he started the Buckeyes’ first 12 games last season and won 11 of them. Everyone knew redshirt-junior Cardale Jones — who did win the Buckeyes the title — would be full go this spring, but Barrett was a question mark.After fracturing his ankle in the regular-season finale against Michigan, Barrett was expected to be very limited in spring ball. But while he is still limited, he’s been well-ahead of the curve.With a three-way quarterback competition wide open between him, Jones and redshirt-senior Braxton Miller, even the limited reps Barrett is getting could be the difference between a starting job and a cozy spot on the sidelines.4. Bri’onte Dunn could (finally) be an impact playerWith Samuel repping with the H-backs and Elliott still recovering from a pair of wrist surgeries, Dunn, a redshirt-junior, has been getting the bulk of the reps at running back in practice.He’s a player billed for greatness coming out of high school who hasn’t lived up to the hype. In fact, Dunn was a rare true freshman who ended up redshirting as a sophomore. Now with another two seasons of eligibility remaining, he seems to be turning a corner.Meyer said he gained momentum as a special teams standout last season, but Dunn will have his sights set on carrying the ball rather than making tackles this time around.If he impresses throughout practice and in the Spring Game, you can bank on Dunn having more than his nine carries for 63 yards from last season in 2015.5. Depth might be an issue again at defensive lineRedshirt-freshman defensive lineman Sam Hubbard (49) is one of a few young players with a chance to earn significant playing time during spring practice. Credit: Mark Batke / Photo editorEvery time the OSU defensive line has come up this spring, Meyer’s mood at the press conference podium has been noticeably sour.He preached throughout last season that the Buckeyes needed to be able to rotate more players in the trenches, but it never quite came to fruition.Now halfway through spring practice, the Buckeyes still don’t seem to have that depth. Defensive-lineman-turned-offensive-lineman-turned-defensive-lineman Joel Hale, back for a fifth year, has added some leadership to the group, but OSU is still looking for other players to step up alongside junior Joey Bosa and senior Adolphus Washington.Young players like sophomore Jalyn Holmes have a chance now and need to take advantage of that opportunity through OSU’s Spring Game on April 18. If not, Meyer might still be pining for more linemen when the Buckeyes take the field against Virginia Tech on Sept. 7 in Blacksburg, Va., to open the 2015 regular season.