The Denver Post says the Broncos "want to give [Montee] Ball the first chance at becoming their No. 1 running back in 2014." It's very unlikely that free-agent Knowshon Moreno will return to the Broncos in 2014, making Ball the most likely lead ball carrier for the Broncos.
Denver RB's aren't going to sneak up on fantasy owners this year. With defenses doing their best to slow down the passing attack, Knowshon Moreno rushed for over 1000 yards and 548 yards receiving out of the backfield. With him out of the picture in Denver, Montee Ball will be given the chance to rack up some big numbers himself.
Assuming Ball holds on to the football through camp and the preseason, be prepared to pay for the second year back who averaged 4.7 YPC his rookie year. If Denver doesn't take a RB in the first half of the draft or grab a "big name" free agent (MJD? McFadden? Meh), both scenarios unlikely, expect Ball to be off the board by the midway point of the second round of your draft.
For now, C.J. Anderson is the most likely change of pace back for the Broncos, with Ronnie Hillman also contributing. It is worth noting that Knowson entered camp last year as a long shot to make the team, so nothing is set in stone.