Is this the end for Moreno? (USATSI)

It's every running back's worst nightmare: lingering and ongoing knee issues. Knowshon Moreno is currently dealing with that nightmare and now, according to Omar Kelly of the South Florida Sun-Sentinel, Moreno won't be playing in the NFL for all of the 2015 season -- all because of his knee. 

For Moreno, this is a serious blow to a career that was beginning to shape up nicely. After recording more than 1,000 yards for the Broncos in 2013 -- the only time he has gone over 1,000 yards in his six-year career -- Moreno signed with the Dolphins prior to the 2014 season.

At the beginning of last season, Moreno seemed poised to follow up 2013 with yet another solid season. In his first 31 carries of the season, Moreno was averaging 4.8 yards per carry. Then, Moreno tore his ACL and was forced to miss pretty much the entire season (side note: Moreno actually briefly stayed in the game after tearing his ACL).

If Moreno does in fact miss all of 2015, he'll come back in 2016 as a 29-year-old running back with an injury history. That does not bode well for his future prospects, and it's hard to see a team offering Moreno a decent deal next offseason. 

He could always sign an incentive-based contract, but considering his age and injury history, it's tough to imagine Moreno bouncing back in a big way, which is sad given his promising season in 2013 and the fact that he was drafted by the Broncos with the No. 12 overall pick in the 2009 draft. Moreno's situation serves as yet another reminder as to why teams are now so hesitant to spend a first-round pick on a running back, though the Rams just drafted Todd Gurley No. 10 overall, despite Gurley's ACL tear in his final season at Georgia. 

Hopefully Gurley has better luck than Moreno.