Doing so as part of the same sport?
That's new to him.
Clemson's 6-foot-2, 325-pound sophomore defensive tackle raised some eyebrows last spring when he walked across the parking lot from the Tigers' football complex to play a season of baseball with Jack Leggett's team, serving as a first baseman.
Last week at Maryland, Reader took duality to a new level.
He got his first career start at defensive tackle opposite Grady Jarrett, and also worked as a fullback in offensive sets near the goal line.
That extra work is just another day at the office for Reader.
"It's been fun getting out there, showing my athletic ability," he said. "It's pretty good to have my coaches trust me enough to have me out there on offense."
During his high school career in Greensboro, N.C., Reader played both sides of the ball, working as an offensive guard and a defensive tackle. Clemson was actually one of the few schools to recruit him as a defensive tackle – he chose the Tigers over Maryland on national signing day 2012.
He made an immediate impact as a freshman defensive tackle, rolling up 40 tackles over 236 snaps in 13 games.
This fall, coaches approached him in preseason practice about serving as a fullback, a plan that went into action just before the N.C. State game.
"We've been working on it ever since," Reader said. I'm always ready when (the offense) gets about 40 yards in and going in. I played offensive guard a lot in high school – it's pretty easy to transition. It's fine, whatever I have to do to help the team. It didn't bother me at all."
Reader's role has only grown this fall. Through eight games, he has 204 snaps with 25 tackles and two sacks.
Last fall, he worked primarily at nose guard behind Grady Jarrett, but this fall he has expanded his workload to excel at the defensive tackle, or three-technique. He is the fourth player to start at that spot this season, joining Josh Watson, DeShawn Williams and Carlos Watkins.
"I'm finally getting the hang of it, playing both," Reader said. "I'm comfortable playing where (defensive tackles coach Dan Brooks) needs me at the time."
Getting a start was special, too.
"It meant a lot," Reader said. "It was my first start, so it was really good to get out there. I was pretty nervous going into it. It was one of the rare times we got to go on defense first, so that was pretty fun."
With Watkins likely facing a redshirt after being involved in a car accident in late September, the rotation has been thinned out, leaving Watson, Williams and Reader to handle the load.
"It's really good competition," Reader said. "It's always good competition in our meeting room. We push each other all out, and all look after each other, so it makes for a great time."
Still, even with Watkins out, Clemson has improved depth on the line, which tends to show itself over the course of 60 minutes.
"We go out there and the way we think about it is that every down's a paw drill," he said. "We're starting to attack more on the pass. Having that rotation, those fresh legs, we use them as a force. We just always try to stay low and play together."
Following last season, Reader went immediately into the baseball season, and didn't get much of a break between sports, given football's year-round training schedule.
He said he hasn't spoken with Leggett about returning for his sophomore season on the diamond and hasn't been participating in fall practice.
But even if Reader never plays another inning for Clemson's baseball team, his dual-threat status appears secure.
CLEMSON - D.J. Reader spent his first year on the Clemson campus playing two sports, football and…