The Detroit Lions have entered the field to begin warming up against the New York Giants.

Several key players put in a lot of work over the course of two days of training in the scorching heat at the Giants’ training ground.

Rookie cornerback Terrion Arnold, who frequently faced wide receiver Malik Nabers in joint practices, has agreed to play, but it is not yet clear how many series the No. 24 overall pick will play in.

In recent years, teams have chosen to leave out key players as the fear of serious injuries means that younger players and those battling for a place in the squad play a significant part in the preseason.

Head coach Dan Campbell explained to 97.1 The Ticket before kickoff what he expects from second-year quarterback Hendon Hooker.

“The first thing is, run the offense, man. Just get us in the right game, be quick and efficient. Just say it,” Campbell said. “Make sure you force the tempo of the offense and make the right decisions. Obviously, we always want an accurate throw. But more importantly, man, he knows exactly where to go with the ball, he knows exactly what to expect in the run game.

“Okay, maybe it wasn’t 100 percent on point, but we can work on that. The mental side is the other ten guys are relying on you to do your job, so just start there,” Campbell continued. “We don’t need the incredible pass. Just do your job, and if it’s not there, double check it.”

Live Blog: Follow the Lions’ season opener against the New York Giants

After reviewing the players who will not be wearing the new “313” uniform at MetLife Stadium, here are those:

David Montgomery, Ifeatu Melifonwu, Jameson Williams, Kalif Raymond, Amon-Ra St. Brown, Jared Goff, Carlton Davis, Jahmyr Gibbs, Kerby Joseph, Alex Anzalone, Malcolm Rodriguez, Jack Campbell, Alim McNeill, Derrick Barnes, Penei Sewell, Graham Glasgow, Taylor Decker, Kevin Zietler, Frank Ragnow, Sam LaPorta, Brock Wright, Levi Onwuzurike, Josh Paschal, Kyle Peko, Aidan Hutchinson, Brian Branch, Marcus Davenport, Emanuel Moseley, John Cominsky, DJ Reader and Christian Mahagony.