ENGLEWOOD, Colo. -- As the Denver Broncos gather Monday for the start of their offseason program, a shift on offense is decidedly on the way.

When tight end James Casey was signed Saturday he joined tight end Owen Daniels among the Broncos’ free-agent acquisitions. When the Broncos looked at their own rather substantial list of impending unrestricted free agents earlier this year, the one player they chose to re-sign to a multiyear deal was tight end Virgil Green.

Casey is a Swiss Army knife sort of player who can also line up at fullback, a position that will make a return in the new scheme after an extended absence. But overall it has been a clean sweep this offseason as coach Gary Kubiak, offensive coordinator Rick Dennison and executive vice president of football operations/general manager John Elway have all openly discussed the importance of the run game in the new offense.

Kubiak has repeatedly said that if the Broncos run the ball better, their ability to pass the ball when they want to will improve in bigger moments.

It all means, as the Broncos open their offseason program Monday with three weeks of conditioning work before moving into more football-specific items over the next two months, the Broncos offense will have a far different feel than it has of the last two seasons.

Whether or not that works out remains to be seen, but the Broncos did set the league’s single-season scoring record in 2013 and averaged 34 points a game over the last two seasons combined. That’s getting it done to be sure. But both of those seasons ended in games in which the Broncos simply did not look like the best-prepared team with an offense that didn't have an answer to how the day was playing out.

Last season, the Broncos had just three games when they were in a two-tight end formation more than they used three wide receivers. In two of those games, wide receiver Wes Welker was suspended for violating the league’s policy on performance-enhancing drugs. All three were before Halloween.

When the Broncos rolled up 42 points on the San Francisco 49ers on Oct. 19 they were in three-wide for 49 snaps (including penalty plays) as compared to one play with two tight ends and even in that two-tight end set the Broncos used three wide receivers as well. They followed the 49ers win with a 35-point effort against the San Diego Chargers when they were in a three-wide set for 52 snaps compared to eight snaps with two tight ends to go with nine additional snaps with either three or four tight ends in the formation.

At that point the Broncos were 6-1 and had scored at least 31 points five times in seven games and had topped 40 points twice.

But then the New England Patriots made a defensive tweak. They played a lot with a single safety deep, taking away the Broncos’ favorite routes in the middle of the field and forcing the ball to the sideline. The Broncos could not run them out of that look and others teams followed suit the rest of the way.

Over the final nine games of the regular season, the Broncos topped 30 points three times and two of those were against the Oakland Raiders, including one win over the Raiders when the Broncos were in a three-wide set (77 times) on every play that didn't involve a kneel-down. Toss in continued struggles in the offensive line to go with Peyton Manning’s eventual thigh injury and opposing defensive coordinators were emboldened that they had solved the puzzle.

It all can be seen in the bookend nature of the season. The Broncos won the season opener over the Colts, 31-24, with 361 yards of offense. In that game, they converted 50 percent of their third-down plays and Manning finished with three touchdowns.

Against the Colts in the opener, the Broncos were perhaps the most balanced in their formations as they were in any game of the season -- 37 snaps in three-wide, 36 with two tight ends. Fast-forward to January when the Broncos faced the Colts in the divisional round.

In the playoff game, the Broncos had their second-lowest scoring output of the season (13 points) against a Colts defense that didn’t finish the season in the league’s top 10 in total defense (11th), scoring defense (19th), run defense (18th) or pass defense (12th). In the game they were in a three-wide set on 56 snaps as compared to 15 two-tight end looks and one snap with three tight ends. The Colts got to Manning, who finished with 211 passing yards, 20 incompletions and made several shaky decisions and that’s-not-like-him throws.

So, as the Broncos begin to get down to the business this week of beginning their offseason program, it’s clear they believe a little more muscle could lift everybody.