ENGLEWOOD, Colo. -- The pain in Denver Broncos running back Devontae Booker's left wrist just wouldn’t go away and when he arrived Wednesday for his customary pre-training camp physical an X-ray revealed the problem.

Booker, who was set to compete for the No. 1 running back job as training camp opened, has a wrist fracture and will now have surgery Friday to insert two screws to aid the healing. He is expected to miss six weeks.

After Thursday’s practice, Broncos coach Vance Joseph said Booker told the team's training staff the pain in his wrist wouldn’t go away during the players' time off between minicamp and training camp, particularly when he tried to train.

“It was a small injury, it was a little sore, it wasn’t serious," Joseph said. “So he went home for the summer and had trouble bench pressing. It was really sore when he braced the bar. Again thought nothing of it, and then he was having his camp physical [Wednesday] and it was still a little sore ... so we X-rayed it and it was a wrist fracture."

Because he hasn’t participated in a training camp practice, Booker was formally designated as physically unable to perform (PUP).

“He could play with this, but the concern is his long-term-health," Joseph said. “... I feel bad for Book because he’s put so much work in and he’s ready to make a push."

Booker had been told he had earned work with the first-team offense when camp opened. Asked earlier Wednesday about the rotation at running back when practiced opened Thursday, Joseph had said C.J. Anderson and Booker would split the carries with both the first- and second-team offenses. Then asked if that meant Booker would get some carries with the starting offense, Joseph quickly replied: “Absolutely, he’s earned that."

On Thursday, Anderson took most of the work with the starters -- the Broncos spent the day in red-zone work in team drills -- as the Broncos plan to regulate how much work Jamaal Charles gets in practice throughout training camp. Charles, who signed a one-year deal with the Broncos in free agency, had played in eight games in the last two seasons combined because of knee troubles.

Joseph said “nothing has changed" in the battle for running back spots given that Booker is expected back just before the regular season. Bernard Pierce, Juwan Thompson and rookie De'Angelo Henderson will split carries behind Anderson.