ENGLEWOOD, Colo. -- As the 2008 season concluded, former Broncos coach Mike Shanahan assembled his coaches and scouts and spoke of a bright future.
He looked at an offense that had Jay Cutler, Brandon Marshall, Eddie Royal, Ryan Clady, Tony Scheffler and other established starters. He told the staff that this offense was set for years and the next offseasons could be used to upgrade the defense. What blindsided him was his firing and the hiring of Josh McDaniels to replace him.
McDaniels, a Bill Belichick understudy, won fans over with a 6-0 start last season, but all of a sudden, the Broncos' offense looks so much different and more uncertain than what Shanahan envisioned after 2008. Cutler, Marshall and Scheffler are gone and an offensive line that seemed to be set for years is undergoing a major renovation.
Add injuries to the mix and you wonder if it is humanly possible for McDaniels to get off to a fast start. He has an older, veteran defense that was put together to win now, but injuries have destroyed all continuity on offense. There are certain defensive packages that could put as many as nine players in their 30s on the field, which could point to a possible fade in the second half of the season if age catches up.
Here are three observations from Broncos camp:
• The offensive line could end up starting second-round choice Zane Beadles at left guard and third-round choice J.D. Walton at center. In a conference that features plenty of 3-4 defenses and powerful nose tackles, quarterback Kyle Orton, who isn't the most mobile signal-caller, could face a lot of schemes in which defenses try to crash the middle of the line to bust Orton's pocket. A good test for Walton is going against powerful nose tackle Jamal Williams every day in camp. Williams has his way with Walton, but the constant beating could only make Walton better, in the same way Steelers linebacker James Harrison helped left tackle Max Starks improve.
The key to the season is getting back left tackle Ryan Clady. McDaniels sounds optimistic Clady could be ready for the regular season, but there are plenty of doubts. Clady blew out a patellar tendon in his knee playing basketball in late April. The hope was to have him back in eight weeks, but sometimes these injuries take eight months to heal. I watched Clady walk across a parking lot to a pair of steps, and he needed both hands on the railings to get up the steps. That's not a good sign.
Even worse are the replacement options. Journeyman D'Anthony Batiste has moved ahead of Tyler Polumbus at left tackle. Batiste was a castoff from a struggling Redskins offensive line. If Clady isn't ready for the season, the Broncos might have to scramble to get a left tackle. The right side should be solid with Ryan Harris at right tackle and Chris Kuper at right guard.
• With Demaryius Thomas and Eric Decker fighting foot injuries, the passing offense is struggling even though Orton is throwing the ball well. The best receiver on the field Wednesday was veteran Brandon Lloyd, who has a history of doing well during the preseason and then becoming inactive during the regular season. McDaniels should feel fortunate he has Orton, his designated replacement for Cutler. Orton threw for 3,802 yards last year for a Broncos offense that was in transition from Shanahan's style to McDaniels'. He makes up for his lack of mobility with smart decision-making and accurate throwing in the short and intermediate areas of the field.
What you worry about while watching practice is if there are going to be enough of the passing parts on the field to get ready for the team to make a fast start. Thomas has shown flashes of greatness during camp. Over the weekend, he was making great receptions, but he's still raw and learning. Orton is making a conscious effort to get the ball to Eddie Royal, a slot receiver who appeared to lose his confidence in a 2009 season in which he caught only 37 passes. Brandon Stokley and Jabar Gaffney are veterans who know their roles, but it will be hard to replace the big-play ability of Brandon Marshall, who was one of the top go-to receivers in football.
• The biggest surprise of my training camp visit was seeing Jamal Williams, who looks refreshed and revitalized in his move from San Diego to Denver. Williams has been one of the league's most dominating nose tackles, but knee injuries started catching up to him in recent years. A torn triceps muscle in the Chargers' season opener ended his career in San Diego, but it could give him hopes of a decent season with the Broncos. He's 34, but his body didn't take its normal pounding last season. If the Broncos can get 30 to 40 plays a game out of Williams, that should help a running defense that surrendered 2,059 yards (4.5 yards per rush) last season.
Justin Bannan is an upgrade at left defensive end. The curious move is that Ryan McBean is still starting at right defensive end ahead of former Patriot Jarvis Green, who signed a four-year, $13.2 million contract. McBean is a big run-stopper and the coaching staff is not ready to get him off the field. Another positive sign is a recent run of good practices by 2009 first-round pick Robert Ayers. Ayers struggled as a rookie, but with Elvis Dumervil likely out for the season, a light has been turned on in Ayers' play. He's been moved to Dumervil's right outside linebacker spot and is making plays on running and passing plays. The secondary remains in good shape with the combination of cornerback Champ Bailey and safety Brian Dawkins in charge. Bailey, still an amazing talent, is 32 years old but hasn't lost any of his skills. He says he can still run a 4.3 40. Dawkins is a smart playmaker who loves to hit.
John Clayton, a recipient of the Pro Football Hall of Fame's McCann Award for distinguished reporting, is a senior writer for ESPN.com.