A former Philadelphia player who accused Eagles coach Chip Kelly of a lot of nasty things has left town a sore loser. A former Philadelphia coach who has questioned Kelly's offensive system is up next at Lincoln Financial Field and he brings with him a big-time winner.

Nothing Arizona Cardinals coach Bruce Arians has said in the past contained the kind of jilted vitriol that LeSean McCoy aimed at his former coach after being traded to the Buffalo Bills during the offseason. Still, Arians' opinions about zone-read offensive systems and quarterbacks who run an up-tempo offense that relies on cue-card instructions from the sideline have made for interesting debate.

This all started in 2013, the first year that Kelly took over the Eagles and Arians, the long-ago Temple head coach, took charge of the Cardinals. Before the teams met in a December game at the Linc that year, Arians stirred the pot by calling the "read-option" system "a great college offense" that put quarterbacks in harm's way. The insinuation was that it would not have a long shelf life in the NFL.

Kelly corrected Arians by pointing out that the Eagles ran a "zone-read" offense and not a "read-option" before also noting that "I don't care what other people think."

The Eagles held on for a 24-21 win over the Cardinals that season on their way to an NFC East title. McCoy, interestingly enough, had this to say about Arians afterward: "College offense or not, he'd love to have some of our players on his team."

Who knew that Kelly would not even want those players on his team by the beginning of his third season?

Flash forward to 2014 and the teams met for a second straight season, this time in the Cardinals' spaceship-like stadium out in the desert. Arizona won the rematch, 24-20, without Arians offering any further criticism of the zone-read offense.

After the season, however, Arians went back on attack during the February scouting combine in regards to up-tempo, spread offensive systems like the one employed by Kelly and the Eagles.

"So many times you're evaluating a quarterback who has never called a play in the huddle, never used a snap count," Arians said. "They hold up a card on the sideline, he kicks his foot and throws the ball. That ain't playing quarterback. There's no leadership involved there. There might be leadership on the bench, but when you get them and they have to use verbiage and they have to spit the verbiage out and change the snap count, they are light-years behind."

With Round 3 of the underrated little rivalry between the Eagles and Cardinals set for Sunday, Kelly was asked Monday what he thought about Arians' criticism.

"I don't know what version of up-tempo he's talking about, so I don't understand that," the Eagles coach said.

Truth is, Kelly has a ton of respect for Arians and the Cardinals. It is challenges like this one that make the NFL a more desirable place than the college game for Kelly.

"You have a really talented football team that is going to come in here," Kelly said. "We played them two years ago here and it was an extremely close game. We played them down there [last season] until the last play of the game. We know we have our hands full."

Despite playing drastically different systems, the Eagles and Cardinals were on similar paths during their first two seasons under Kelly and Arians. That has changed this season with the 6-7 Eagles still in the race only because of the division they are in and the 11-2 Cardinals among the league's elite teams.

Arizona's offense is second in scoring and first in total yards and its defense has allowed the seventh fewest points and fourth fewest yards. The Cardinals have more offensive weapons than any team in the league, which is why quarterback Carson Palmer is being mentioned as an MVP candidate.

"He's so sharp and can change things at the line of scrimmage and put them in the right protection, put them in the right routes, so you've got to give them a lot of different looks," Kelly said. "You have to attack them a lot of different ways."

In other words, Palmer does things at the line of scrimmage that Arians believes are taken away from quarterbacks in up-tempo systems.

Regardless of which system you think is best, this game against the Cardinals is a chance for the Eagles to prove they can be something more than a team that backed into the playoffs should they be able to win their weak division.

"You'll really get some believers then," linebacker Brandon Graham said. "The Cardinals are 11-2 and a lot of people are probably going to have us to lose that game. But we're the underdogs, baby. I love it. All we have to do is accept the challenge and put in the work and everything will take care of itself on Sunday."

Lose and the Eagles will still be able to win their division. Win and they might convince themselves they can do even more than that.