On Monday, Charles Robinson of Yahoo Sports reported the NFL has asked arbitrator Stephen Burbank to review information brought forward in the case's 14 depositions, including those with commissioner Roger Goodell and Dallas Cowboys owner Jerry Jones, to determine whether there's "sufficient evidence" to continue or if the league and its teams can be cleared, ending the motion.
Kaepernick, who's been an unrestricted free agent since opting out of his contract with the Niners in March 2017, filed the collusion grievance in October.
The 30-year-old Wisconsin native drew media attention for starting the movement to kneel during the United States national anthem before NFL games.
"I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color," he told NFL Media in August 2016. "To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder."
In the collusion filing, Kaepernick's legal team argued those actions, and not his on-field performance, were the reason he wasn't being signed.
"[The NFL and its owners] have colluded to deprive Mr. Kaepernick of employment rights in retaliation for Mr. Kaepernick's leadership and advocacy for equality and social justice and his bringing awareness to peculiar institutions still undermining racial equality in the United States," the filing read.
In December, Goodell said during an appearance on CNBC's Squawk Box he didn't believe Kaepernick was being "blackballed" by the league's owners.
"Each and every club's got to make those decisions," he said. "They make those decisions based on a lot of factors that are best for their football team. And when they do that, that's what's in the best interest."
Adam Schefter of ESPN reported Kaepernick's planned visit with the Seattle Seahawks in April was canceled after the quarterback wouldn't assure the team he'd stand for the anthem if signed.
Meanwhile, NFL owners approved a new anthem policy for the 2018 season that forces players to either stand on the sideline or remain in the locker room for the anthem. Teams that have a player violate the rule will be subject to a fine.