OXNARD, Calif. (AP) -- Charles Tapper churned on an exercise machine early one morning at training camp, drawing a rebuke from the staff of the Dallas Cowboys for overdoing things when the defensive end turned up sore after missing all of his first season with a back injury.
Tapper can't help but think of himself as another rookie alongside first-round pick Taco Charlton, also a pass rusher, even though the former Oklahoma player has been in the NFL a year longer.
He didn't play a down in 2016, preseason included, before joining Charlton in the Hall of Fame game last week.
Both are promising young players trying to lift a Dallas pass rush that's been mediocre or worse for three straight seasons, two of them playoff campaigns that might have been longer if the Cowboys had put more pressure on Green Bay's Aaron Rodgers, who beat them both times.
"I feel like we're in the same boat," said Tapper, who was chosen 34 picks before star rookie quarterback Dak Prescott in the fourth round last year.
"Because I feel like I'm a rookie all over again. I'm still striving for that first (regular-season) game, still trying to get that first sack and I'm still hungry for it."
The Cowboys believe Tapper's speed can make him an effective rusher, and they drafted Charlton out of Michigan because of his height (6-foot-6), long arms and athleticism.
Dallas got Charlton with the 28th pick after finishing with the best record in the NFC (13-3) and losing to the Packers in a divisional playoff.
It was the third time in four drafts the Cowboys took a defensive end in the first two rounds.
DeMarcus Lawrence (second round, 2014) is looking for a breakout season after back issues slowed him his first three years.
Randy Gregory (second round, 2015) is a washout so far, suspended for at least the regular season because of multiple substance-abuse violations.
The possibility that Gregory's career is over essentially before it started rates as one of the biggest reasons Charlton and Tapper are important.
"We count on both of them because they're young, good, young legs, fast, they're healthy," defensive coordinator and defensive line coach Rod Marinelli said. "We've got to get that part out of them. We've got to."
Charlton, who had 9 sacks as a senior at Michigan and 18 for his career, didn't shine much early in his first camp. He played 16 snaps in the 20-18 Hall of Fame win over Arizona, but didn't show up in the tackle stats.
In the past five Dallas drafts, the first-round picks have started at least 11 games as rookies. Three of them -- center Travis Frederick, right guard Zack Martin and 2016 NFL rushing leader Ezekiel Elliott -- were walk-in starters, and the only game missed between them was Elliott sitting for the regular-season finale last season when the Cowboys had already clinched the top seed in the NFC.
"Right now I'm just working with the best, working to earn my spot on the defensive line," said Charlton, who has dealt with minor back soreness in camp. "We're a deep, veteran group. The first couple of days I came out to earn my keep and work into the starting group."
Three defensive ends will be suspended to start the season: Gregory, David Irving (four games, performance-enhancing drugs violation) and Damontre Moore (two games, substance-abuse violation). The most experienced end, Tyrone Crawford, might be out to start the season after badly spraining his right ankle in camp this week.
Just add the looming opportunity to the list of reasons coaches, medical personnel and teammates have had to chastise Tapper for not pacing himself. He's admittedly anxious.
"You want to get back to yourself as quick as possible," said Tapper, who has battled some hip soreness in camp. "You're like, man, I'm not getting off as fast as I used to. You want to rush that process to getting back into it. You can't rush the process. It's the process for a reason."