Ed Werder breaks down what the possible return of Randy Gregory could mean for the Cowboys' defense. (1:20)

FRISCO, Texas -- Defensive end Randy Gregory went through his second straight day of full practice and has caught the eye of Dallas Cowboys defensive coordinator Rod Marinelli.

“He’s looked good. I mean, he’s so explosive off the ball. That’s all the same. He’s thicker. He’s bigger. He’s gained weight,” Marinelli said. “And he looks really good but now I think as you go, it’s not so much winning the rush, it’s building the foundation to rush, if that makes sense, [with] his get-off and his pad level. I just want him to get to work and go, and then he can, I think, if he’s doing that he’ll help us impact the game.”

Gregory missed the first 14 games due to suspensions for violating the NFL’s substance abuse policy. He was only cleared to practice Monday, but he had been working out with the team’s strength and conditioning coaches and taking part in the defensive meetings.

Like when defensive end DeMarcus Lawrence returned from a four-game suspension earlier this season, Marinelli believes Gregory will be good enough this Monday against the Detroit Lions, but they will have to monitor his work.

“Your body is just not used to it, the hitting,” Marinelli said. “And now you kinda go through training camp, you get broken down and you go through it and then you come back. We just got to be smart, monitoring how many snaps he gets. They’re a bunch of car crashes out there at the end of the day. So we understand it, and we got to work through it.”

With Lawrence out because of a recurring back issue and defensive tackle Tyrone Crawford slowed by shoulder and hamstring injuries, Gregory will get the opportunity to get up to speed quickly.

He did not have a sack as a rookie and has not played in a game since last year’s season finale, but Marinelli doesn’t have low expectations for the former second-round pick.

“No, I go in with expectation of improving,” Marinelli said. “I just want him to come off. I want the fundamentals down for him because if those aren’t there, he won’t keep growing and that’s what I want. I want good growth for him.”