Denver Broncos RB situation

Rookie Montee Ball likely to start, but what about his backup?

The Denver Broncos are a team with a conundrum at RB. Not at who to start, but rather who to let go.
The drafting of Montee Ball in round 2 of last month's draft should effectively spell the end of Willis McGahee as the starter. Ball is younger, and has been the most productive RB in college football over the last 2 years. He should fit the Broncos offensive scheme to the proverbial "tee" as he reads blocks well, powers thru the hole with decisiveness, and is very underrated catching the ball out of the backfield. All in all, Ball has feature RB attributes and will succeed as a rookie (in part because of opponents not being able to key on him because of Peyton Manning and the Broncos WR corps).
But what about the two RB's who were both productive last season? Willis McGahee was on his way to another 1,100+ yards season before getting injured. Knowshon Moreno came in afterwards and proved to be capable of handling primary RB duties. One of these two is going to be let go.
Let's flash back to before the start of the 2012 season. At that time, Moreno was considered to be firmly on the roster bubble. His history of inconsistent on-field production and off-field incidents had him widely considered to be a long shot to make the final 53 man roster. It was a surprise the Broncos kept him and an even bigger surprise when they turned to him to be their primary RB when McGahee went down with a torn MCL and broken leg in November. Moreno put up 510 rush yards, 3 TD's, and 20 receptions over the last 6 games of the season.
McGahee was cruising along to a surprising 2012 campaign thru the first 10 games gaining 731 rush yards, 4 TD's, and 26 receptions before his leg injury. It wasn't expected that McGahee would produce so well for a RB on the wrong side of 30 years old. But he was. A healthy McGahee may have even been able to make a difference in Denver's playoffs fortunes. He clearly was the top RB over Moreno for Denver until the injury.
I expect that by the time we get to training camps, this situation should work itself out, but maybe not. It seems fairly clear cut that with McGahee being due $2.5 million in 2013 and turning 32 years old in October that he is the odd man out. Moreno is younger (he turns 26 years old in July), and due less money ($1.7 million on the final year of his original rookie contract). With Ball slated to be the feature RB, it should only make sense that the younger, cheaper guy should be kept, right?
Not so fast.
I think this is going to linger on into preseason. I think the Broncos want to see two things before making a decision here. First they want to make sure Moreno doesn't have any off-field incidents. And second, they want to see how McGahee's leg has recovered. Older veteran RB's who have proven to be effective like McGahee still have a place in today's NFL. They make excellent fall back options in case of injury or unmet expectations by younger RB's. The monetary difference between McGahee and Moreno is miniscule by today's standards and with Moreno very likely to leave via free agency in 2014, it's possible the Broncos mindset may be that they are much more likely to be able to sign McGahee to a new low cost contract after this season as a veteran backup to Ball than Moreno.
The impact this has on fantasy football is small. Whoever the top backup to Ball turns out to be will be nothing more than a handcuff for a fantasy roster. But it's one that right now, I don't think is as cut and dried as some think.