John Fox tried to warn everybody.

Don’t read anything into Montee Ball taking the first-team tailback reps Monday, the Broncos’ coach said.

Naturally, with an estimated 19 million people setting their Fantasy League rosters this week, Fox’s heed was ignored.

So who was the Broncos’ primary first-team running back during practice Tuesday? Ronnie Hillman.

“I don’t even know yet, so I don’t know how you all know,” Fox said about who the Broncos’ starting running back will be this season. “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.”

Ball’s place with the first-string offense Monday was significant for two reasons. One, Hillman had been the No. 1 back every day since the start of offseason practices in May. He had hoped to carry that streak at least until Sept. 5, when the Broncos open the season at home against the Baltimore Ravens.

“I’d be lying if I said I didn’t,” Hillman said Tuesday. “I’m still working toward that right now. We’ve got one more week.”

And two, Ball was inserted among the starters Monday as Hillman was coming off back-to-back preseason games in which he fumbled and his fumbles were returned for touchdowns.

As a teaching tool, the Broncos had Hillman carrying a football between reps Monday and Tuesday.

“I’m going to do what they want me to do,” Hillman said. “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.”

A big deal was made of the rookie Ball — the most prolific running back in NCAA history after he was finished playing for the Wisconsin Badgers — taking the first-team reps Monday. Ball occasionally mixed in with the first team again Tuesday, but Hillman took more.

“I don’t listen to what you all talk about,” Hillman said, laughing. “You all might tick me off. So I don’t listen.”

Mike Klis: mklis@denverpost.com or twitter.com/mikeklis