The partnership doesn't include the former San Francisco 49ers quarterback -- a fact that was not lost on his supporters -- and came on the heels of the third anniversary of Kaepernick's historic protest on the field.
Attorney Mark Geragos, who represents Kaepernick, described the deal in a phone interview with ABC News on Monday as "cold-blooded."
"This deal between Jay-Z and the NFL crosses the intellectual picket line," Geragos said, adding that neither the NFL nor Jay-Z reached out to Kaepernick during discussions.
"I can confirm to you that the deal was already done prior to any conversation that [Kaepernick] had with Jay-Z and he certainly didn’t have any conversations with the NFL," Geragos said.
ABC News has reached out to the NFL and Jay-Z's label, Roc Nation, but requests for comment were not returned.
Kaepernick, who hasn't played in the NFL since 2016, was propelled into the national spotlight when he became the first NFL player to take a knee during the playing of the National Anthem to protest racism and police brutality on Aug. 14, 2016.
Reid, who now plays for the Carolina Panthers, has continued to take a knee and has repeatedly slammed Jay-Z and the NFL over the deal.
"We never advocated for Colin to lose his job while we fought against systemic oppression. That’s unjust, and where the NFL inserted itself into this. Now the NFL is 'championing' social justice to cover their own systemic oppression in blackballing Colin. So we will fight to get Colin’s job back as well," Reid wrote in a series of tweets responding to a video of ESPN's Stephen A. Smith, who pushed back against critics of the NFL and Jay-Z, arguing, "wasn't that the goal that Colin Kaepernick had?"
"Jay-Z knowingly made a money move with the very people who’ve committed an injustice against Colin and is using social justice to smooth it over with the black community," Reid added.
During a press conference on Wednesday, Jay-Z and NFL Commissioner Roger Goodell discussed details of their new partnership.
"I think we've passed kneeling," Jay-Z said when by a reporter asked if the rapper would kneel or stand if he were playing. "Yeah, I think it's time to go into actionable items."
Kaepernick has not directly addressed the deal, but a Saturday tweet with a photo of Reid, and Miami Dolphins players Kenny Stills and Albert Wilson taking a knee appears to push back against Jay-Z's statement.
"My Brothers @E_Reid35 @KSTiLLS @iThinkIsee12 continue to fight for the people, even in the face of death threats," Kaepernick tweeted. "They have never moved past the people and continue to put their beliefs into action. Stay strong Brothers!!!"
Kaepernick filed a grievance against league owners in 2017 alleging that they colluded to ensure that he remains unsigned -- a sore point for activists who point to his status as a free agent to argue that the NFL's efforts to amplify social justice are disingenuous and an effort to save face.
Reid, who became a free agent for several months before he signed a one-year contract with the Panthers last October, also filed a grievance against the NFL in May 2018 alleging that they colluded to keep him out of the league. Both lawsuits have been settled.
Jay-Z, who has supported Kaepernick and the protests, said during the press conference that he is "not minimizing" the protests but added that the protests were "not about a job," but about "injustice."
"Let me bring attention to injustice. Everyone's saying, 'How are you going forward if Kaep doesn't have a job.' This wasn't about him having a job," Jay-Z said. "That became a part of the discussion. He was kneeling to bring attention to injustice. We know what it is. Now how do we address the injustice?"
Earlier this year, Jay-Z joined forces with fellow rapper Meek Mill and launched a criminal justice reform organization. Its executive board includes Jay-Z and Kraft Group CEO and New England Patriots owner Robert Kraft.
Over the past three seasons, the backlash against the NFL's handling of the protests and a firestorm against players who take a knee have prompted boycotts of NFL games from both sides.