CLEMSON -- Speed earned Roderick McDowell a nickname -- 'Hot Rod' -- and elite prospect status as a star running back at Sumter High.

While always possessing acceleration and shiftiness, the redshirt freshman was missing football substance this spring, according to the staff.

In Clemson's first summer football scrimmage Tuesday, McDowell showed a new resolve, the ruggedness and utility of a light pickup truck in rushing for a team-best 76 yards on 12 carries.

"He's tougher," Clemson coach Dabo Swinney said. "I thought he was pretty soft this spring. He's really been a more competitive, more focused player in camp. He's running the ball with more authority. He's finishing plays that aren't necessarily there, second-effort type plays, bouncing off the first hit."

The development is of more consequence than his 5-9, 180-pound frame suggests.

Not only does Clemson lose rare explosiveness with the departure of C.J. Spiller, the Tigers also lose depth.

Running backs are often dinged -- or worse. Jamie Harper and Andre Ellington, reserve backs from a year ago, are now in line for a timeshare. But beyond the starting tandem is not a single carry of experience at tailback.

Clemson offensive coordinator Billy Napier was not ready to anoint McDowell as a 100-carry reserve like Harper and Ellington were behind Spiller last fall, and McDowell needs to add strength, but Napier did not rule out a significant role for McDowell.

"He's really passionate about what he's doing," Napier said. "He just continues to give great effort."

While McDowell has added toughness, the speed and explosion remain. McDowell had rushes of 22 and 34 yards Tuesday.

Napier listed McDowell as one of his three rising offensive players after the first seven days of practice. Napier also included tackle Phillip Price, a converted tight end, and tight end Drew Taylor.

"I think those guys have done some good things," Napier said. "(They) had a great offseason and are serious about doing their jobs."

Price was a part of a second-team offensive line that had success moving the ball on the ground against the second-team defense.

Defensive coordinator Kevin Steele's first-team unit limited the offense to 2.4 yards per carry, an effort he called "substantial," and both the first- and second-team units -- even without defensive end Da'Quan Bowers, who was absent mourning his father's death -- were effective against the pass.

Starting quarterback Kyle Parker posted a line of 9 of 18 passing for 114 yards, while backup Tajh Boyd was 7 of 18 for 71 yards. Boyd did cap a scoring drive with a 13-yard touchdown run, showing his knee is 100 percent following ACL reconstruction last year.

Ellington rushed for 45 yards on 11 carries, and Harper added 35 yards on seven carries. But it was McDowell leading the rushers, beginning a candidacy for an expanded role this fall.

"He continues to show signs," Swinney said. "He might make himself relevant."

Who wants the ball?

The wide receiver competition, perhaps the most contested position battle this summer at Clemson, remains a race still too close to call a week into camp.

No Clemson wide receiver stood out statistically Tuesday, as six receivers tied for a team-best two catches.

Swinney indicated Marquan Jones might be creating separation at the slot receiver position, but said the outside positions still have as many as eight players competing for two spots.

Reach Travis Sawchik at tsawchik@postandcourier.com, check out the Clemson blog at postandcourier.com/blogs/tiger_tracks.