Vance Joseph was proven correct.

The Denver Broncos’ woes weren’t just the fault of Trevor Siemian.

Continuing their worst stretch of football since 2010, the dreaded final season of Josh McDaniels, the Broncos were whipped by the Philadelphia Eagles, 51-23, here Sunday on an overcast, but mild, early November Sunday at Lincoln Financial Field.

“It starts with me,'' Joseph said. "I’m the head coach here, it starts with me. I’ve got to fix this.''

The Eagles had been up 44-9 when their star quarterback Carson Wentz was pulled with 3 minutes left in the third quarter and given the rest of the day off.

It's the first time the Broncos had surrendered 50 points or more since losing to the Oakland Raiders, 59-14, in 2010, a season that ended with a 4-12 record.

"It’s the truth, 51 points, and the offense, they did what they needed to do today,'' said Broncos outside linebacker Von Miller. "You can’t put anything on offense. Offense had been better than what they usually had been doing. And defensively we were like, if we can just get that part we’ll start winning. We got that part today and our defense, we just (wet) the bed.’’

There were times when the vaunted Denver D didn't seem to show much fight as it missed way more tackles than usual. Eagles recently acquired running back Jay Ajayi scored on a 46-yard run and Corey Clement had his first, two touchdown game.

The Broncos settled for two consolation touchdowns in the fourth quarter, the first a 1-yard pass from Brock Osweiler to Demaryius Thomas, and the second came off a Von Miller strip sack fumble against backup quarterback Nick Foles. Broncos linebacker Brandon Marshall recovered the fumble and returned it for another touchdown. Thomas' short score snapped his touchdown skid of 13 games.

“That was a good play. Everybody kept going, kept fighting,'' said Broncos cornerback Chris Harris Jr. "They had their backups in there, though. That doesn’t even count. That was my first game playing against the backups. We’re not very good right now.’’

Before then Osweiler, who started in place of the benched Siemian, led the Broncos to three, Brandon McManus’ field goals, while Wentz, the sensational second-year quarterback, was leading the Eagles to touchdowns.

The Broncos’ season is becoming a disaster. After a 3-1 start, the Broncos came out of their bye week wearing the motivational saying “MORE” across their workout T-shirts and an inexcusable home loss to the then-winless New York Giants.

The Broncos’ season has only become worse. They are 3-5 with a home game against the defending Super Bowl-champion New England Patriots up next.

"I think anytime you lose a game like this there are going to be some discouraged people, but we need to shake that off on the flight back to Denver,'' Osweiler said. "Come to work tomorrow with a positive mindset, and ready to learn from our mistakes and fix them because there is a lot of football to be played.''

The Eagles won their seventh straight and improved to 8-1.

An unexpected problem for the Broncos was their defense played poorly allowing three long touchdown drives each time on the next possession after McManus converted field goals. McManus, who was born here, raised in the area, and played college ball at Temple, made all three field goal attempts of 52, 53 and 24 yards.

Each time, the Denver D couldn’t follow with a stop.

Joseph, the Broncos’ first-year head coach, made his first quarterback switch of his career this week as he replaced the turnover-prone Siemian with the veteran Osweiler.

On the first drive of the game, Osweiler completed passes of 14 yards to Thomas and 19 to Cody Latimer to get close enough for McManus to boot a 52-yard field goal.

All the Broncos needed was for their No. 1-ranked defense to come through with a stop and momentum would be with the visitors.

The defense, though, appeared dispirited from the start. Wentz picked up a third-and-9 with a quick pass to backup tight end Trey Burton for 14 yards.

The Broncos thought they had a third-and-1 stop but star cornerback Aqib Talib was called for holding. With Talib upset at the call, the Eagles went right back at him, and Wentz hit a wide-open Alshon Jeffery for a 32-yard touchdown. Talib declined comment after the game.

Osweiler did throw an interception that hurt. He threw a slant pattern to Thomas, who was beaten to the ball by cornerback Patrick Robinson, who returned to the Broncos’ 15.

On third down, Wentz slipped an inside screen to running back Corey Clement who ran to daylight for the touchdown.

While that score wasn’t necessarily on the Denver defense, it was otherwise no match for Wentz and the creative Eagles’ offense. Wentz completed a relatively modest 15 of 27 passing for 199 yards, but he also threw four touchdowns with no interceptions.

Osweiler was 19 of 38 for 208 yards with one touchdown and two interceptions. The Broncos also struggled to run the ball as C.J. Anderson, Jamaal Charles and Devontae Booker combined for 35 yards on 19 carries.

Both head coaches made some curious late-game decisions given the blowout situation. The Eagles not only went for it on fourth down with 5:34 left and a three touchdown lead, Foles completed a 35-yard deep pass down the right sideline to Nelson Agholor.

Joseph called two timeouts inside of 2 minutes and his team down by four touchdowns.

“That was my decision,'' he said. "We’re just finishing playing the game, that’s my personality. I want to see who is going to finish the game tonight.”

Both coaches shook hands and exchanged pleasantries at midfield after the game.

“I have no problem with how they played the game,'' Joseph said. "It’s our job to stop them. I have no problem at all with that.”

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