Ronnie Hillman was the Broncos' primary first-team running back during practice Tuesday, a day after rookie Montee Ball filled the role.
"I don't even know yet, so I don't know how you all know," coach John Fox told the Denver Post when asked who will start the season opener. "They'll both carry a big load for us this season, knock on wood. Whether it's '1A' and '1' or however you want to list it, they're both very capable and we're very pleased with both."
Hillman had been the No. 1 back every day in practice until Monday. But he was coming off consecutive games in which his fumbles were returned for touchdowns. Coaches made Hillman carry a football in between reps Monday and Tuesday, the Post said.
"I'm going to do what they want me to do," Hillman told the paper. "I've never had fumbling problems before. I just can't let it get in my head and handicap me. I have to go out there and continue to play."
Ball got some first-team snaps Tuesday, but Hillman took more, according to the report.