NFL notebook: Arbitrator rejects NFL bid to dismiss collusion case

Colin Kaepernick's grievance against the NFL will move forward after an arbitrator denied the league's request to dismiss the collusion case. The NFL had sought to have Kaepernick's case scuttled but arbitrator Stephen Burbank nixed the motion. Pro Football Talk, citing a source, reported that the ruling will give Kaepernick and his attorney, Mark Geragos, more chances to gather information as to why the quarterback has been unable to secure employment in the NFL. A free agent since he opted out of his contract with the San Francisco 49ers in March 2017, Kaepernick filed a grievance against the NFL in October 2017 that accused the 32 owners of collusion. Kaepernick has been a controversial figure since he first sat and then knelt during the national anthem before games while with the 49ers in the 2016 season as a protest against police brutality against African-Americans, social injustice and racial inequality. --Linebacker Elvis Dumervil announced his retirement from the NFL over social media. "After spending a great deal of time talking to my family and prayerfully considering what's next in my career, I have a made the difficult decision to step away from the NFL at this time," Dumervil wrote on Twitter. "It's been an incredible 12-year run." Dumervil played in all 16 games last season, recording 13 tackles and a team-high 6.5 sacks after signing with the San Francisco 49ers on June 6, 2017. Dumervil, 34, finished with 105.5 sacks, which is 26th on the all-time list. Dumervil recorded a pair of 17-sack seasons -- one each with the Denver Broncos and Baltimore Ravens. --Tight end Rob Gronkowski had his contract restructured by the New England Patriots on Thursday, multiple media outlets reported. Gronkowski's agent, Drew Rosenhaus, announced the revised deal via social media, posting congratulatory posts to his client on Twitter and Instagram. Per ESPN and the NFL Network, Gronkowski can receive a maximum of $13.3 million salary in 2018 that will include up to $4.3 million in additional incentives. Gronkowski, who is signed through the 2019 season will receive $1 million in game bonuses and can earn three additional $1.1 million performance incentives. In what could be a related move, New England backup tight end Dwayne Allen agreed to take a pay cut to remain with the team, ESPN reported. Allen, who was scheduled to make $4.5 million this season, had only 10 receptions in 2017. --Arizona Cardinals rookie quarterback Josh Rosen will sit out the team's final preseason game on Thursday, according to a published report. NFL Network's Steve Wyche reported that Rosen will be afforded extra time to get healthy for the regular season as he nurses a thumb injury on his throwing hand. Rosen sustained the injury while hitting his hand on a teammate's helmet in practice. Rosen, who was the 10th overall pick of the 2018 draft, did not participate in the Cardinals' third preseason game. He completed 16 of 29 passes for 148 yards and a touchdown in his two previous preseason contests. Quarterbacks Mike Glennon and Chad Kanoff are expected to play in Thursday's preseason game against the Denver Broncos. --Seattle Seahawks linebacker K.J. Wright is not expected to be ready for the team's regular-season opener. Coach Pete Carroll told reporters that Wright's arthroscopic knee surgery went well on Monday. When asked for how long the 29-year-old Wright would be sidelined, Carroll said that "they talked about a couple weeks. It was the most optimistic we could be." Should that timetable ring true, rookie Shaquem Griffin likely would start in Wright's place as the Seahawks face the Broncos in Denver on Sept. 9. Griffin will have a chance to work alongside linebacker Bobby Wagner when the Seahawks close the preseason Thursday against the visiting Oakland Raiders. --Jacksonville Jaguars cornerback Jalen Ramsey doesn't hold New England Patriots tight end Rob Gronkowski and Miami Dolphins wide receiver Danny Amendola in high regard. Ramsey, who blasted a number of NFL quarterbacks in a recent interview with GQ, poured proverbial cold water on Gronkowski during a session with ESPN The Magazine. "I don't think Gronk's good," Rasmey said of the four-time All-Pro and five-time Pro Bowl selection. "Let me say -- I don't think Gronk is as great as people think he is. "Any time Gronk has been matched up with a corner, he's had a very bad game," the All-Pro said, "and that corner has had a very good game." --Miami Dolphins quarterback Ryan Tannehill said he feels he's playing "with more confidence" as he nears his official return from a knee injury. In fact, Tannehill told the Palm Beach Post that he believes he's about to embark on the best season of his career. "Totally believe that," Tannehill said. "Totally believe that. I am more prepared than I have ever been. To play the position. Everything it encompasses. Physically. Mentally. Emotionally. I'm more solid than I've ever been. I'm more consistent fundamentally than I've ever been. Play comes in. I know exactly what I have to do. Boom. Boom. Boom." Tannehill is expected to start when Miami opens the season against the Tennessee Titans on Sept. 9. --The Dallas Cowboys are hoping to keep ailing center Travis Frederick on their 53-man roster. Frederick has been sidelined while dealing with Guillain-Barre syndrome, a rare disorder in which the body's immune system attacks the nerves, and no definitive timetable has been given for his return. However, Cowboys executive vice president Stephen Jones told the team's official website that Frederick will remain on the active roster after it is whittled down to 53 players on the weekend. "It's still too early. We won't make that decision, probably until next Monday," Jones said. "As we all know, regardless, he'll be on the team when we cut to 53, and then we'll make decisions from there." --Indianapolis Colts rookie defensive lineman Tyquan Lewis is expected to miss nine weeks with a foot injury, according to a report. The Indianapolis Star's Zak Keefer reported the length of time that Lewis is expected to miss due to injury. Lewis was selected by the Colts with a second-round pick in the 2018 draft. Colts coach Frank Reich didn't put a timetable on Lewis' return on Monday. "No surgery, just hasn't been coming along as fast as we would've liked," Reich said, via Colts Wire. "No, we are hopeful we will have him. We're hopeful we will have him." --The Houston Texans signed offensive lineman Greg Mancz to a two-year contract extension, the team announced. Financial terms were not disclosed for the deal, which will keep Mancz with Houston through the 2020 season. An undrafted free agent out of Toledo in 2015, Mancz is entering his fourth season with the Texans. The 6-foot-4, 310-pound Mancz appeared in 10 games, making seven starts, during the 2017 season. He started five games at center and made two starts at right guard. The 26-year-old Mancz started all 16 regular-season games and two postseason contests at center in 2016. He was the only lineman on the club to start every game. --The Tampa Bay Buccaneers waived running back Charles Sims with an injury settlement, the team announced. The release of Sims came one week after the team placed Sims on injured reserve. Sims suffered a knee injury on the opening kickoff of Tampa Bay's second preseason game against the Tennessee Titans on Aug. 18. Sims, who was re-signed by the team on the eve of the NFL draft in April, was entering his fifth season with the Buccaneers. A third-down draft pick of Tampa Bay out of West Virginia in 2014, Sims appeared in all 16 games in 2017, serving primarily as a third-down back. He had only 21 carries for 95 yards and added 35 receptions for 249 yards and one touchdown. --Washington Redskins running back Adrian Peterson wasn't too pleased with the recent criticism fired his way by Hall of Fame players-turned-television hosts Cris Carter and Shannon Sharpe. Speaking on FS1's "First Things First," Carter said he sees Peterson's career ending with a thud in much the same manner that he experienced during his one year in Miami. Playing in his 16th NFL season, a then-37-year-old Carter was limited to just eight receptions while playing in five games with the Dolphins in 2002. "Did you see me in a Dolphins uniform?" the 52-year-old Carter told USA Today. "I had no business playing that season. I wouldn't have admitted it, either. These guys get so sensitive about everything. Adrian had better get over himself. We were all great. But at the end, we all smelled like a baby's diaper." "Watching some of the things they said about me, man, it really hurt me to the core," Peterson told USA Today. "Not only are they black men, but these are people I looked up to. And these are people that made mistakes, especially Chris Carter. So some of the things that came out of his mouth, not only personally, but about me as a player -- Aw, he's washed up and this, that and the other, and he should just retire -- how dare you." --The Oakland Raiders reached an injury settlement with wide receiver Griff Whalen, the Las Vegas Review-Journal reported. The move came three days after Oakland placed Whalen on injured reserve due to turf toe. If Whalen does sign not with another club, he will be eligible to re-sign with Oakland in Week 7. Whalen signed with the Raiders in March after spending last season with the Baltimore Ravens. In 14 games with the Ravens, including two starts, Whalen had only four receptions for 23 yards. --Former NFL running back Trent Richardson signed a contract with the Birmingham team in the Alliance of American Football. Richardson struggled in his career following a strong rookie season after being selected by the Cleveland Browns with the third overall pick of the 2012 draft. "Excited about this," Richardson told al.com about joining the AAF, which is a new, eight-team league that is scheduled to begin play in February. "Another opportunity for my professional career. Happy to be doing something that I really love doing, especially in Alabama and in Birmingham, which is a home away from home for me." Richardson rushed for 950 yards with the Browns in 2012 before being traded to the Indianapolis Colts for a first-round pick, which later resulted in Cleveland selecting quarterback Johnny Manziel.