ENGLEWOOD, Colo. –The offseason addition of quarterback Peyton Manning to the Broncos offense has exposed opposing defenses to much different looks than they saw a year ago.

But one thing that remains familiar to Broncos' opponents is the success of veteran running back Willis McGahee, who is averaging 4.7 yards per carry and has piled up 325 yards and three touchdowns through four weeks. McGahee's effectiveness is a reflection of the entire offense, which has opened up the holes and let McGahee take care of the rest.

"He's worked extremely hard," McCoy said. "All of last year, this year, he's bought into our system and he's playing with a great offensive line. The guys up front have done a great job opening up holes. The back is only going to be as good as your offensive line is. Then the fullbacks, tight ends, blocking and all those things. The whole group, all 11 guys, have helped him out and going back to last year, the way (wide receiver) Demaryius (Thomas) and (wide receiver) Eric (Decker) and (wide receiver) Matt (Willis) and those guys blocked outside, you block the right guys, you block the secondary support down there and he gets the crease and he's off and running. All 11 guys on offense have helped him but he's a strong runner and he's made the most of his opportunities since last year."

While McGahee has gotten the majority of the touches, another player who is beginning to emerge in the backfield is rookie Ronnie Hillman. After not dressing for Weeks 1 and 2 while recovering from a hamstring injury, Hillman saw his first action against Houston, then carried the ball 10 times and caught two passes for a total of 63 yards in the Week 4 win over Oakland. McCoy said he expects Hillman's role to steadily increase as the season progresses and the rookie becomes more comfortable.

"Any young player, the more reps they get, the better they're going to be," McCoy said. "So over time, we'll cut a plan for him. It's one of those things we said sitting down and coming in to training camp what we wanted to do with him and as the season goes along he'll get more work and just take it day to day and keep learning the system because there's a lot of new things that are thrown at him. The number of different looks he's seeing defensively from week to week and the game's a lot faster but it's still playing football. He's doing a nice job and just taking it one day at a time and learning as he goes."

GREEN JOINS TIGHT ENDS

One of the strengths of the Broncos through the first four games of the season has been the play of a pair of tight ends in their first years in Denver.

Already one of the offense's focal points, the tight end position was further bolstered this week, as Jacob Tamme and Joel Dreessen, who have combined to catch 22 passes for 200 yards and three touchdowns, will be joined by second-year man Virgil Green. After sitting out the first four weeks of the season due to a suspension, Green rejoined the team Monday, giving the Broncos yet another option at tight end.

"It's great to have him back," Offensive Coordinator Mike McCoy said. "He worked extremely hard this offseason and did a nice job all through training camp. He's another one of those 'Y' tight ends that can put his hand on the ground, we can flex him out, he does a nice job of blocking so it's nice to have him back around to help everybody out."

Green, Tamme, Dreessen and second-year pro Julius Thomas give Manning a quartet of targets who are at least 6-foot-3, with the strength to impact the run game and the athletic ability to split out wide. The Broncos' versatility at tight end is just one example of what has become a popular trend throughout the NFL.

"I think league-wide, athletically the talent the tight ends have now is unbelievable," McCoy said. "It's very similar to defensive ends. The way colleges are playing football now with the tight ends out there running all over the place, they're almost like a receiver to a certain extent but they're just bigger. It doesn't surprise me at all, throughout the entire league, the success tight ends have because it's a mismatch for certain teams and they do a nice job with it."

KOPPEN AND MAGAZU TOGETHER AGAIN

Center Dan Koppen had a lot of adjustments to make when he signed with the Broncos on Sept. 11 after spending his first nine seasons with the New England Patriots.

One familiar face greeting him upon his arrival in Denver was that of Offensive Line Coach Dave Magazu, who worked with Koppen back at Boston College. Both Magazu and McCoy have been familiar with Koppen since their days on the Carolina Panthers' coaching staff, so they were excited to bring Koppen on board.

"It's great to have him," McCoy said. "Dave Magazu's been trying to get him since he came out. We were in Carolina together, Dave and I, and when he was coming out and Dave wanted him back then and he had him in college also so he's familiar with the way Dave coaches and running the similar system in New England, some of the terminology and some things that we call the same so it was an easy transition for him. He's done a nice job."

McCoy said he looks forward to seeing what Koppen can do against his former team this weekend and throughout the rest of the season.

"He'll be familiar playing against those players but he's a crafty veteran," McCoy said. "He's been around long enough so regardless of who the opponent was, we have a lot of confidence in him."