In the pass-happy NFL, Denver Broncos quarterback Peyton Manning had 4,659 passing yards with 37 touchdowns in 2012. He has a talented group of wide receivers and when he’s not throwing the ball he has plenty of running backs to help on the ground.

Some may say too many.

As the Broncos started their OTAs last week, they have a crowded running back field with eight players. This number will be whittled down with the contenders already at the top of the depth chart with a few surprises hoping to emerge. Some are veteran players, a talented rookie and those looking to improve/jumpstart their NFL careers.

Let’s take a look at this stable, beginning with the experienced running backs; some would say three’s a crowd.

The true veteran and the oldest guy of the bunch, is talented Willis McGahee. He is entering his 11th league season and questions are lingering.

McGahee signed with the Broncos in 2011 (after four seasons with the Baltimore Ravens) and had a good first year under former quarterback Tim Tebow with almost 1,200 yards (4.8 yard average carry).

But 2012 was a not a repeat as the player tore his right MCL after Game No. 10, ending his season. He also brought a history of injuries from his Ravens days to Denver.

In 2013, he’ll celebrate his 32nd birthday and a $2.5 million salary. Will he become a salary cap casualty or a has-been from a bad knee?

Pinch hitting for McGahee in 2012 was Knowshon Moreno. He is now in his fifth NFL season and has also struggled with injuries. One included a season-ending ACL-injury in 2011 as well as hammy problems.

He was the not greatest runner last season with 3.8 yards per carry but he did have 525 rushing yards with four touchdowns. After a successful NCAA career at Georgia, he’s been somewhat of a NFL disappointment.

Ronnie Hillman is starting his sophomore season. He’s ready to improve (3.9 yards per carry last season) with 330 yards and one touchdown. He stepped up in the playoff loss to the Ravens with 83 yards and no fumbles.

Hillman has added 20 pounds in the offseason and has worked out hard after a hamstring injury and weight loss slowed him down in his rookie season; he’s now ready to be a solid contributor after being the NFL’s youngest player in 2012 (20).

Hillman should make the team’s roster.

Now meet rookie running back Montee Ball.

The Broncos picked him up in the second round after the player underwent a very successful college career at Wisconsin: he was the NCAA’s all-time touchdowns leader and in 2011 as a junior, the Heisman Trophy runner-up. He should see some playing time in 2013.

With Ball and Hillman on the roster, will it come down choosing between McGahee or Moreno?

There’s also the second Ball on the team, Lance Ball.

This is his fourth year with Denver and he played in 15 games last season, carrying the ball 42 times with 158 yards and one touchdown. He had no starts.

Ball sits behind the four aforementioned players and 2012 may have been his last year on the Broncos roster.

Then there’s there’s the three Odd Men Out.

Lance will be challenged to make the team will fellow backs, Jeremiah Johnson, Mario Fannin and C.J. Anderson, who need to overcome greater odds.

In 2011, Johnson played eight games for the Broncos including postseason play. He joined the team at the end of 2010 roster on the practice squad and has no stat line from 2012.

Next up is Fannin. A member of the 2010 national championship-winning Auburn team, he joined the Broncos in 2011 as an undrafted free agent. He’s yet to see any playing time as he’s been out for two seasons with injuries.

Anderson is the green player in this group as he joined the team this offseason from Cal. In his senior year, he had 126 for 790 yards (6.3 average carry) with four touchdowns. This includes three 100-yard rushing games.

Johnson wins on experience to gain a spot but who’s to say Fannin may not come roaring back or Anderson could shine under Manning–as most players do.