Sielski: Do Eagles have ground game to protect Wentz?

There are many ways for an NFL team to protect a rookie quarterback, and make no mistake: Unless that rookie quarterback is Dan Marino, Peyton Manning, or Andrew Luck, an NFL team should be doing all it can to make the young player's transition to the league as smooth as possible. A team can implement a more conservative game plan, to lessen the demands on the kid. It can keep an extra receiver or two in to block on pass plays. It can trust its defense and special teams to tip each game's balance in its favor.

Of course, the easiest way to protect a rookie quarterback is to not play him while he's a rookie, but when it comes to Carson Wentz, the Eagles already have dispensed with that approach. He's going to play, beginning Sunday against the Cleveland Browns, and he's going to require more protection than most rookies. For all the fulsome praise that Wentz has received for his physical skills, his intelligence, and his demeanor, it's worth noting how little experience he has at actually being a quarterback.

Remember: He was 5-foot-8 and 125 pounds when he entered Century High School in Bismarck, N.D., and did not become the varsity starter until his senior season. At North Dakota State, he was the Bison's starter for less than two full years, missing half his senior season with a broken wrist. In his didn't-really-count debut for the Eagles, he threw 24 passes against the Tampa Bay Buccaneers' third-team defense before fracturing two ribs and sitting out the rest of the preseason.

The notion, then, that having Wentz as their starter will allow the Eagles to expand their playbook immediately - for example, to be more daring because Wentz is more willing and better able to throw the football downfield than Sam Bradford - seems far-fetched at best. They will probably have to protect him, which means they will probably have him hand the ball to their running backs often, which means coach Doug Pederson will have to answer some questions and carry out some calculations about those backs, if he hasn't already.

Let's establish, first, a baseline for those calculations. Over Pederson's three years as their offensive coordinator, the Kansas City Chiefs ran an average of 982 offensive plays: 504 passes thrown, 433 rushing attempts, and 45 quarterback sacks, and Pederson and Andy Reid oversaw a rather unadventurous offense relative to the rest of the NFL. Their quarterback was Alex Smith, the consummate "game-manager" at the position. They leaned on their running backs, especially Jamaal Charles. In 2014, they went a whole season without having a wide receiver catch a touchdown pass. The Kansas City approach is a fair approximation of what Pederson might want the Eagles offense to look like this season, if he wants to protect Wentz. If anything, Pederson ought to call even more running plays, to lighten the burdens on Wentz and the Eagles offensive line.

Such a strategy would in turn put more responsibility on the running backs: Ryan Mathews, Darren Sproles, Kenjon Barner, and Wendell Smallwood - Mathews, in particular.

"He looks good," offensive coordinator Frank Reich said early last month, before the Eagles had played their first preseason game. "He's an explosive, physical runner. . . . With the track record he has and the way he's run the ball over the last few years, we want to get him as many touches as we can."

But how many touches can Mathews, the prospective workhorse of the group, reasonably be expected to handle? He has averaged 171.5 carries during his six NFL seasons, never more than 285 in any of them, and he has missed 23 of a possible 96 regular-season games because of various injuries. Last year, he suffered a concussion and a groin injury and sat out three games, and that was during a season in which he carried the ball just 106 times.

Sproles' 83 carries last season were the second-most of his 10-year career; he has averaged just 57.7. Barner has all of 34 carries in his two years in the NFL. The Eagles like Smallwood's skill set, but his straight-up-and-down running style would seem to make him susceptible to hellacious hits from opposing defenders. And sure enough, after sitting out most of training camp with a quadriceps problem, he carried the ball twice against the Indianapolis Colts before one of those hits forced him out of the game and into the league's concussion protocol. (Pederson said Monday that Smallwood has since returned to practice.)

So, let's say that the Eagles need to get 433 rushing attempts - the Chiefs' average during the Reid-Pederson years - out of their backs this season. I'd argue that figure is low, but let's go with it. In a best-case scenario, Mathews (285) and Sproles (83) would provide 368 carries, minimizing what would be required from Barner and Smallwood. But if Mathews and Sproles have seasons of average workloads, they would combine for just 230 attempts, leaving Barner and Smallwood to account for the remaining 203. And if Mathews gets hurt again, and if the Eagles (as expected) use Sproles primarily as a receiver and limit his number of carries, then the demands on those less-experienced backs, Barner and Smallwood, will necessarily increase.

The demands on Wentz will, too, which is not the best way to protect a rookie quarterback, assuming the Eagles are actually interested in doing so.

msielski@phillynews.com

@MikeSielski