ENGLEWOOD, Colo. -

Running back Montee Ball is clear-cut as a starter compared to, say, quarterback Peyton Manning. But as the Denver Broncos progress through organized team activities, the competition at running back revolves entirely around who will back up the second-year veteran -- who has never started an NFL game.

Knowshon Moreno was the clear first-teamer last year, and had a career season, finally looking like the first-round pick he was when the Broncos drafted him in 2009. But Ball was a second-round pick in 2013, and was not added to be the lesser-used half of a platoon.

"We drafted him in the second round to be a big contributor," said offensive coordinator Adam Gase. "I know I keep saying the same thing, but you know we do have a lot of confidence in him."

The Broncos would not have been comfortable parting ways with Moreno had Ball not flourished at the end of the season. After struggling with fumbling issues most of the season, he overcame them and ran for 297 of his 559 yards in the last five regular-season games. From Week 13 through the Super Bowl, he averaged 5.4 yards per carry, better than Moreno in that same span.

At that same time, Ball also began to better understand the offense. His blitz pickup was quicker and crisper. The light bulb clicked on.

"Yeah, it did. It started happening around Week 12 and you started to see it. I started playing better. A lot more confidence," Ball said. "I wish I had done that early on because I always tell myself, imagine where I would have been at, at the end of the year last year, if I started fast. So that's what I'm doing this year, starting fast and keeping it going every week."

The Broncos will be counting on that. They would like to ease the burden on Manning a bit, and could run a bit more to protect leads than they did in 2013. Given Ball's massive workloads at the University of Wisconsin, they know he can handle heavy use. But they don't want him to, which makes the competition behind him crucial.

Ronnie Hillman, the 2012 third-round pick originally was thought to have the edge and has seen spot duty taking handoffs from Manning during OTAs, along with second-year veteran C.J. Anderson. But Anderson moved past Hillman on the depth chart last year, and questions about Hillman's work ethic, durability and ball security have dogged him since his arrival. Hillman had the chance to seize the No. 1 role last year, but flopped, and by late in the season, was a mainstay on the game-day inactive list.

"I probably got a little relaxed last year leading up to the season, and it carried over," Hillman said. "But it won't happen again."

Hillman and Ball are different types of runners; Ball, at nearly 220 pounds, is powerful and can find holes between the tackles. Hillman says he's playing at 201 pounds; he was drafted for his quickness. That would seem to make Hillman more of a change-of-pace option, although he refuses to cede the role.

"It's easy to say you're going to practice hard and work hard, but you've just got to show it," Hillman said. "Right now is the time. These next couple of months are crucial. The job's open, and I'm going after it. I'm not working to be No. 2."

But if Ball plays as expected, that might be all Hillman or any other running back can get.