ENGLEWOOD, Colo. -- Calling himself a “caged animal,’’ Denver Broncos defensive end Derek Wolfe formally rejoined the league’s No. 1 defense on Monday.

Wolfe missed the Broncos’ first four games of the season -- the team went 4-0 -- because of a suspension for violating the league’s policy on performance-enhancing drugs. In his absence, the Broncos sit atop the league’s rankings in total defense, sacks, pass defense and third-down defense, and they are No. 2 in fewest points allowed.

“I’m ready to go," Wolfe said. "I’m like a caged animal right now."

“I expect him to hop right back in there,’’ Broncos coach Gary Kubiak said. “He’s been working hard. I think Derek’s a guy that takes care of himself. We know the way he can help our football team.’’

Derek Wolfe said it was tough be away from the Broncos when he felt fine physically and was eager to play. AP Photo/David Zalubowski

Wolfe said Monday afternoon that defensive line coach Bill Kollar welcomed him back to the team with a workout to gauge his fitness. Wolfe said he “worked hard, trained hard’’ during the suspension and that at times he scheduled his workouts during the Broncos games to “mimic the game tempo.’’

However, he said watching the team jump out to its undefeated start and seeing the kind of defensive aggressiveness Wade Phillips’ defense has shown thus far, with 11 takeaways and 18 sacks in those four games, was difficult. Wolfe was formally reinstated Monday, and the Broncos now carry a roster exemption for several days, which allows Wolfe to practice with the team before the Broncos have to make a roster move to get to 53 players.

“It was awful. It was awful,’’ Wolfe said. “I’ve had to sit before and watch because of injury, but when you’re perfectly healthy and you’re just chomping at the bit, ready to go and you feel the best you’ve ever felt, there’s nothing worse.’’

Of the defense’s efforts, Wolfe added, “I mean, what hasn’t been impressive? From the back end all the way to the defensive line has been impressive. Stopping the run … I just think that they’ve done -- from the front all the way to the back end -- everybody’s done a great job. … Crazy thing is we can be even better.’’

Wolfe’s return does make a crowded position group, in terms of playing time, even more crowded. The Broncos have kept five defensive linemen active on game days -- Kenny Anunike was a healthy inactive for Sunday’s game against the Minnesota Vikings. Against the Vikings, all five of the defensive linemen in uniform played at least 19 snaps, while Malik Jackson, Sylvester Williams, Vance Walker and Antonio Smith each played at least 30 snaps.

Wolfe worked with the starting defense in training camp and is considered one of the team’s best early-down players. He says he knows and understands that playing time is going to be spread around.

“It gets me excited. You get to come into the No. 1 defense in the league,’’ Wolfe said. “Adding help -- what else can you ask for? It’s like they’re out there getting beat up. They’re out there just dominating.’’

“Obviously, we’ve got quite a few guys there, numbers-wise. There’s some decisions to make,’’ Kubiak said of playing time for the group Sunday against the Oakland Raiders and beyond. “We have a very competitive environment there right now. … That should only make us better.’’