PHILADELPHIA -- By the time the shock from the LeSean McCoy trade wore off, most Philadelphia Eagles fans already knew the team was close to signing DeMarco Murray. There wasn't a lot of time for concern about the team's running back situation to creep in.

It would have been much more trying if fans had to wait until the NFL draft to find out who McCoy's replacement would be. Dallas Cowboys fans can relate. Dallas lost Murray, the NFL's leading rusher, about five weeks ago. The Cowboys signed Darren McFadden, but the expectation remains that they will draft one of the running backs available at the end of this month.

Despite the fan comfort factor, it's fair to wonder if coach Chip Kelly would have been better off waiting for the draft, too.

ESPN draft analyst Todd McShay said he has seven running backs with grades that make them worth selecting in the draft's first three rounds. The best of them, Todd Gurley, is coming off a torn ACL. As we know from the Eagles' trading for Sam Bradford and Kiko Alonso, that wouldn't deter them for a moment.

But the larger issue was raised when Gurley was talking about the durability of running backs in general.

"I'm not a big fan of spending early picks on running backs," McShay said. "I certainly wouldn't re-sign [Gurley] and dump a boatload of money into him on the second contract. You look over recent history in the league and with the salary-cap restrictions, you just can't afford to pay too much at the running back position. You've got to free up money for quarterbacks, offensive tackles, pass-rushers and cover guys."

When he signed Murray, Kelly said he hoped that Murray would be around to sign another contract with the Eagles.

At that point, Murray will be 31 years old. He will have counted $9 million per year against the Eagles' salary cap for the previous three seasons. Maybe the Eagles will want him back as a role player, but it seems hard to imagine he'll command the kind of money he's getting on this contract.

Kelly cited McCoy's $12 million cap figure as a prime reason for making the trade. McCoy is still 26, a few months younger than Murray. But he was already playing on his second NFL contract.

McShay's point is the running back position has been devalued in the NFL. The trend may be for teams to draft backs in the middle or late rounds and then use them for a few years before moving on. It's rare to see teams make the kind of investments the Eagles made in McCoy and Murray.

Kelly now has three runnings backs -- Murray, Ryan Mathews and Darren Sproles -- all making fairly large salaries. That is reassuring for fans who were stunned by the McCoy deal. But it may be that Kelly would have been better off saving the money he spent on Murray and Mathews and scooping up a young back at relatively low pay in the draft.