And for Johnson, the system is pretty much as he expected when the Eagles hired Kelly away from the University of Oregon in January.
"When I heard that Coach Kelly got hired, the one thing that just lit up in my mind was thinking, 'Oh, man, it's going to be a spread offense. He's going to give guys the chance to have the ball in space, and I know that that works to my advantage,' " Johnson said Wednesday.
Jackson and Maclin will likely be the No. 1 and No. 2 receivers. But there's no reason to think that Johnson can't be the third option, although there will be plenty of competition for catches with three starting-caliber tight ends and three ball-catching running backs.
Johnson's forte has always been what he could do once the ball was in his hands. He set the NCAA record for all-purpose yards (7,796) at Tulsa despite missing his senior season after being suspended for his involvement in a merchandise scam at Macy's.
Last season, he averaged a promising 11.2 yards per punt return that included a 98-yard return for a touchdown against the Cowboys. He also averaged 51/2 yards after his 19 catches, a respectable number he could certainly improve upon, and one he said he would.
"I always say, 'Who wants to get hit?' " Johnson said. "That's how I look at it. I don't want to get tackled, so I'm trying to dodge the guys as much as I can, put a move on them, and just get yards after the catch."
Still, Johnson said he spent the offseason looking to gain strength to help him break tackles. The 5-foot-8 receiver said he gained five pounds and weighs 170. It's a small sample, but the 23-year-old was featured as much as any other receiver during the Eagles' two open spring practices.
"He's going to look good, obviously, in shorts," general manager Howie Roseman said. "He's got exceptional quickness. He's got long speed. And the big thing for him is continuing to develop his strength and then when the pads come on."
Of the receivers battling for playing time after the starters, Johnson is the quickest. Jason Avant, long the Eagles' third receiver out of the slot, averaged just 3.2 yards after the catch last season.
Riley Cooper and Arrelious Benn, significantly larger than Johnson, could be battling for that last roster spot. Both are capable special-teams performers, but Johnson probably has an edge because of his return abilities.
There is talk that Jackson will once again be the primary punt returner, but a platoon is more likely.
"Hopefully, he can do it, I can do it, and we can both be back there at the same time," Johnson said.
Johnson said that he's the No. 1 kick returner. Cornerback Brandon Boykin handled kickoff duties last season but was mostly ineffective. Johnson averaged 251/2 yards per kick return at Tulsa, where he was versatile.
"I'm happy to be here. But at the same time, I don't want to be a guy that's just here," Johnson said. "I want to be a guy that's known. I want to be a guy that my team counts on. I want to be a playmaker. I don't want to be just a man on the 53-man roster."
Veterans in jeopardy. Roseman, who was on a panel with executives from Philadelphia's three other professional sports teams at the Rothman Institute's symposium on "The Impact of Sports," said that there will be certain valuable Eagles who may "fall by the wayside" because of changes in scheme.
"One of the things that's hard for us, and you've seen some of it this offseason," Roseman said, "is we've had players that were good players in different schemes and that we've invested in, and it's not going to turn over."
Contact Jeff McLane at firstname.lastname@example.org. Follow on Twitter @Jeff_McLane.