PHOENIX - Jeffrey Lurie says he believes in the necessity of a franchise quarterback for sustained success in the NFL, and he hopes Sam Bradford can become that player for the Eagles despite an injury-plagued career.

"There was an opportunity to do an upside gamble with an outstanding young quarterback who you hope can become healthier throughout his career," the Eagles owner said Tuesday at the NFL meeting. "It is so hard to get a franchise quarterback, as you know. It sets the ceiling on what you have as a team, and do you want to take upside gambles or not? You've got to make that decision."

Lurie said that in the 2010 draft, the Eagles evaluated Bradford as "the best young quarterback we'd seen . . . probably since Peyton Manning coming out of college." Then Lurie watched Bradford have an "outstanding" rookie season in St. Louis with Pat Shurmur as an offensive coordinator before he was beset by injuries.

If Bradford can become a quarterback upgrade, there would be no need to inquire about a trade for Marcus Mariota. Eagles coach Chip Kelly said earlier this month that the team would not mortgage its future for one player, but Lurie was less emphatic about such a trade.

"It's great to mortgage the future for Peyton Manning. It's not very good to mortgage it for Ryan Leaf," Lurie said. "It's great to mortgage it for Donovan McNabb, but not for Tim Couch or Cade McNown. Again, it comes back to people. It's not a system. If the Redskins had traded for Andrew [Luck], we'd all be saying what a great trade. So, you tell me."

Kelly's first offseason with final say has included seven additions to the roster and departures of popular Eagles LeSean McCoy, Jeremy Maclin, Nick Foles, Trent Cole, and Todd Herremans.

Trading McCoy, who is the franchise's all-time leading rusher, was a controversial decision. Lurie said that McCoy did not fit the running style that Kelly prefers: one-cut, downhill rushers.

"LeSean McCoy is a great running back - all-time franchise leader," Lurie said. "Great guy in every way. To maximize [Kelly's] power spread offense, he's always admired the one-cut runners. That's what he admired. You've got to let a coach try to bring in the players that fit best what he's all about to maximize what he's trying to accomplish."

Lurie also reiterated that the Eagles tried to re-sign Maclin, but they did not want to overspend after Maclin went to Kansas City and the market for wide receiver dried up.

"The sad part is you're dealing with people's lives," Lurie said. "For me, I take it really seriously. It's not easy to talk to Nick Foles for a long time after the trade, or LeSean, Trent Cole, guys that have devoted their lives to us, and are wonderful people."

He disagreed with the idea that the Eagles are subtracting their best talent by pointing out the additions of Kiko Alonso, Byron Maxwell, Bradford, DeMarco Murray, and Ryan Mathews.

"These are excellent young players that you hope will stay healthy and they'll be really good players in the prime of their careers," Lurie said. "When you're trying to go from good to great, you've got to take some gambles, you've got to take chances."