The Ravens have a good problem. They have two running backs who appear worthy of being No. 2 in Bernard Pierce and Bobby Rainey.

Pierce, who the team traded up to select in the third round of this year's draft, is the favorite to win the job while the undrafted Rainey likely will fall into the No. 3 spot after Thursday's preseason finale at the St. Louis Rams.

Rainey, standing 5-8 and 212 pounds -- the exact measurables of Ray Rice -- has proven to be an excellent receiver out of the backfield as he has challenged Rainey, who was limited by hamstring issues early in the preseason. Rainey also has surprised in other areas.

"He's a really smart football player. Usually, the toughest thing for a young running back is pass protection and I would say that might be the best thing he is doing," offensive coordinator Cam Cameron said this week. "He's not a little guy. He's stout. He's not the tallest guy but he's really stepped in and did a great job in pass protection."

In the first two preseason games, second-year running back Anthony Allen failed miserably in pass protection and quarterback Joe Flacco was sacked as a result. Rainey and the other rookies, Pierce and Damien Berry, have dominated the workload. Berry is built in the same mold, two inches taller than Rainey and weighing 223 pounds. Pierce is 6-0 and 218 pounds.

The Ravens aren't worried about having a backfield that resembles one another in stature and skills.

"A good player is a good player," Cameron said when asked about Rainey. "Great players, good players, come in all shapes and sizes. I don't know what the measurable is for a running back anymore. How do you measure a guy's heart? How do you measure a guy's mind? You measure Ray's mind, you measure his heart. You don't even think about what his height is. And this kid may be the same way."