PHILADELPHIA — An arbitrator is sending Colin Kaepernick’s grievance with the NFL to trial, denying the league’s request to throw out the quarterback’s claims that owners conspired to keep him out of the league because of his protests of social injustice.

Kaepernick’s lawyer Mark Geragos tweeted a picture Thursday of a ruling by arbitrator Stephen B. Burbank.

The former 49ers’ quarterback argues that owners have colluded to keep him off any NFL roster since he hit free agency in 2017.

Kaepernick began a wave of protests by NFL players two seasons ago, kneeling during the national anthem to protest police brutality and racial inequality. The protests have grown into one of the most polarizing issues in sports, with President Donald Trump loudly urging the league to suspend or fire players who demonstrate during the anthem.

Kaepernick contends the owners violated their collective bargaining agreement with players by conspiring to keep him off of teams.

The case hinges on whether owners worked together rather than decided individually to not sign Kaepernick.

A similar grievance is still pending by unsigned safety Eric Reid, who played with Kaepernick in San Francisco and joined in the protests.

PASS RUSHER Elvis Dumervil is retiring from the NFL after 12 years.

Dumervil says he wants to spend more time with his family and real estate business.

Dumervil entered the league as a fourth-round draft pick in Denver in 2006. He spent seven years with the Broncos, four more with Baltimore and finished his career last year with San Francisco. He finished his career with 1051/2 sacks. That ranks fourth in the NFL since he entered the league, trailing only DeMarcus Ware, Jared Allen and Julius Peppers.

Dumervil made five Pro Bowls and was a first-team All-Pro in 2009 and 2014.

GIANTS: It doesn’t sound like a compliment to call a quarterback a “complementary” player. But when Kurt Warner used that term to describe Eli Manning at an NFL Network event, he insisted that he meant it in the best possible way.

“It’s not meant as an insult,” the Hall of Fame quarterback and NFL Network analyst said. “When they’ve been good with Eli, it hasn’t been because they throw the ball 40 times on Eli’s arm. That’s what I mean by him being a complementary piece. It isn’t a bad thing. It’s just, there are other guys who are built around throwing the ball 45-50 times and that’s where they thrive. I don’t think Eli thrives there.”

More to Warner’s point, he thinks Manning will thrive this season.

“Eli is really good in the big moments,” Warner said. “If you can not ask him to have to carry the load every snap, every game, I think there’s no question (he still has it) because that’s where he thrives. Give him a good team around him, put him in big moments, and he’ll play well. I think he’s got plenty left in the tank as far as who he is and what he can do. Now they just have to make sure it’s not all based on his right arm.”

CARDINALS: Receiver Larry Fitzgerald said his friendship with Sen. John McCain was a testament to the war hero’s ability to reach out to people from all walks of life.

Inside a packed Phoenix church, Fitzgerald spoke warmly of the time he spent over the years with McCain, an avid fan of Arizona’s sports teams. Fitzgerald said the two of them could not have been more different on the surface.

Fitzgerald said that while he does everything he can to avoid contact as a football player, McCain was the “epitome of toughness.”

He said McCain did not judge others based on skin color, gender or their bank accounts but “the merit of their character and content of their hearts.”

McCain died Saturday after battling brain cancer.

SEAHAWKS: Coach Pete Carroll says linebacker K.J. Wright will miss at least a couple of weeks after undergoing arthroscopic knee surgery earlier this week, making it increasingly unlikely that he’ll be ready for the Sept. 9 opener at Denver.

Carroll said the surgery was successful. But when it came to Wright’s recovery, Carroll said, “They talked about a couple weeks; it was the most optimistic we could be.”