ENGLEWOOD, Colo. -- It is a testament to Tom Brady and the Patriots' offensive game-planning that their offense has remained one of the league's most productive, even as they have coped with a pass-catching corps dented by injury, departure and arrest without bail.

But now, the group is the closest to optimal health as it has been this season. Danny Amendola finally has the chance to settle into his role, and Julian Edelman did well filling in for Amendola; the two have combined for 841 yards on 81 receptions, and have adequately replaced Wes Welker.

But everything flows from tight end Rob Gronkowski.

"They're going to get him the ball one way or another. And we've got our hands full," said Broncos cornerback Champ Bailey. "You wish he'd drop a few passes along the way, but that doesn't happen very often. So we've just to play our good defense and let the chips fall where they may."

Since his return in week 7, Gronkowski has returned to his usual pace; he's averaging six yards a catch and 87 yards a game; he's scored twice; he's been effective down the seam. But his impact extends to the rest of the Patriot's

But since Gronkowski's return, the Patriots' offense has improved -- well beyond the passing game:

• Before Gronkowski's return, the Patriots averaged 4.87 yards per play, 6.4 percent below the average permitted by the six defenses they faced. In the weeks since, they've averaged 5.73 yards per play -- 11.8 percent above what their opposing defenses usually allow.

• Without Gronkowski, New England averaged 5.37 yards per pass play, 9.7 percent below what their opposing defenses yielded. With him, that average spiked to 6.54 yards per pass play, 8.3 percent above the average permitted by opposing defenses.

• Without Gronkowski, Brady completed 56.9 percent of his passes, 5.6 percent below the average allowed by their foes. With him, Brady's completion percentage is up to 61.7 percent, .56 percent above the average allowed by their opposing defenses.

Defending Gronkowski means sacrificing something else, unless you're able to contain him with one defender, all the time -- something the Broncos don't plan to do.

"He's a good player; he'll require more than just one guy," said defensive coordinator Jack Del Rio. "He'll need some attention and his productivity and all that kind of mandates that. But we'll mix it up like we do -- we'll have a plan for it."

The key, overall, is not backing down from Gronkowski, even if he tries to be physical. As Carolina's Luke Kuechly showed Monday night, sometimes physicality doesn't result in a penalty.

"You can chip him, but then you kind of affect your pass rush," said Bailey. "You don't want to spend too much time doing that. But we definitely want to be physical with him as much as we can and hopefully just cover him a lot better than we did in the past."

NOTES:

• The only major offensive metric to take a hit since Gronkowski's return has been the Patriots' sack rate, which has spiked from one every 15.94 pass plays to one every 12.75. But that is due less to having a receiving-oriented tight end in the lineup and more to the season-ending broken leg suffered two games ago by New England right tackle Sebastian Vollmer.

According to ProFootballFocus.com, Vollmer allowed just two sacks and 13 hurries in 311 plays where he worked as a pass blocker. His replacement, Marcus Cannon, has a slightly lower sack ratio, allowing just one in 188 pass-blocking snaps, but has been slightly less effective at permitting hurries.

• Much has been made of the pace the Patriots maintained against the Broncos last year, often snapping the football with between 20 and 30 seconds left on the play clock. But the Broncos' occasional accelerated offensive pace -- and the work the defense had against it in practice -- should mean fewer issues if the Patriots try to move at warp speed this time.