Herron, starting his third straight game, had 12 carries for 56 yards (4.7 average) and a touchdown while leading the Colts with 10 receptions that went for 85 yards.
The trouble -- as it has been all season with Herron -- was that he fumbled, twice.
"You can't do it. You can't do it," coach Chuck Pagano said, per ESPN.com. "He had a great day (Sunday) minus the two times he put the ball on the ground. He understands it, I understand it, everybody in Indy understands it. Everybody in this room understands that you can't put the ball on the ground and there's nothing more precious than the football and possessing the football.
"So we'll continue to address it with him. He's a grown man, he understands it and he understands the ramifications that come with it. He's going to continue to work at it."
Herron was yanked from the game for a spell after his second fumble and Pagano insisted the young back will "get it fixed."
Herron will have to get that fixed quick as he faces a Broncos run defense that ranked second in the NFL, allowing just 79.8 yards per game.