at Sports Authority Field at Mile High on September 13, 2015 in Denver, Colorado.

Evan Mathis knows what it takes to succeed in the NFL.

The 34-year-old has played 11 seasons in the league, and has been considered by most to be the best guard in football over the last several years. Pro Football Focus even ranked Mathis as a top-10 player in the NFL, in every season from 2012-2014. In 2015, Mathis won a Super Bowl in his first season with the Denver Broncos.

Mathis joined the Broncos after asking for a release in January from the Philadelphia Eagles, where he’d spent his previous four seasons. In those final two seasons with the Eagles, Chip Kelly — now head coach of the San Francisco 49ers — was Mathis’ head coach.

In an email on Monday with Broncos beat writer Mike Klis, Mathis ripped Kelly, saying how Kelly couldn’t handle big personalities, and that “The Broncos team I was on would have eaten Chip alive”:

Mathis also stated via e-mail that Kelly is not the type of coach who could have handled the 2015 Broncos’ contingent of outsized characters.

“There were many things that Chip had done that showed me he wasn’t building a championship team,” Mathis wrote in his e-mail to 9NEWS. “Two of the main issues that concerned me were: 1. A never-evolving, vanilla offense that forced our own defense to play higher than normal play counts. 2. His impatience with certain personality types even when they were blue-chip talents. The Broncos team I was on would have eaten Chip alive. I don’t think he could have handled the plethora of large personalities.”

Ouch. Mathis also explained how he asked for his release from the Eagles:

Before Mathis encountered his decision between the Dolphins and Broncos, he first needed Philadelphia coach Chip Kelly to release him from his Eagles contract. Kelly was not willing to rework Mathis’ contract, as the previous Eagles’ regime had.

Most players would use their agent to handle such a task. Mathis directly texted Kelly with a YouTube video of Engelbert Humperdink singing, “Please release me, let me go. …’’

Amazing, and here’s the video Mathis is referring to:

While Mathis’ comments are eye-opening, they certainly come as no surprise given the (poor) reputation Kelly has quickly established in the NFL. Kelly is going to have to make some adjustments to his coaching style and how he relates with players if he wants to succeed in San Francisco.

[9News]

About Matt Clapp

Matt is an editor at The Comeback. He attended Colorado State University, wishes he was Saved by the Bell's Zack Morris, and idolizes Larry David. And loves pizza and dogs because obviously.

He can be followed on Twitter at @Matt2Clapp (also @TheBlogfines for Cubs/MLB tweets and @DaBearNecess for Bears/NFL tweets), and can be reached by email at mclapp@thecomeback.com.