Representatives from all clubs are invited to attend the workout, which will include on-field drills and an interview. Several teams inquired about Kaepernick's football readiness and both he and his reps have expressed a desire to return to the league, Rapoport added.
"Earlier this year, we discussed some possible steps with his representatives and they recently emphasized his level of preparation and that he is ready to work out for clubs and be interviewed by them," the memo reads, according to ESPN's Adam Schefter. "We have therefore arranged this opportunity for him to work out, and for all clubs to have the opportunity to evaluate his current readiness and level of interest in resuming his NFL career."
Kaepernick confirmed the news on Twitter, expressing his excitement regarding a second shot at playing in the NFL.
NFL scouting president Jeff Foster set up the workout, which will take place at the Atlanta Falcons' team facility and be run by former NFL coaches. There will be no media allowed, though Foster and his staff will interview Kaepernick and make the video available to all teams, ESPN's Dan Graziano reported.
As indicated in his tweet, Kaepernick and his representatives weren't notified of the opportunity until 10 a.m. on Tuesday, sources told Schefter, who added that teams also weren't notified until the memo was sent.
Once alerted, Kaepernick's reps asked for the workout to take place on a Tuesday, but the NFL denied that request, according to Schefter. Most workouts occur on Tuesdays, as coaches and general managers can more easily attend, whereas Saturdays are usually used for preparation or travel during the season.
The NFL also reportedly denied a request to move the workout until the following Saturday, which would have given teams more time to decide whether or not to attend and which staff members to send.
When Kaepernick's reps inquired whether a specific team or multiple teams had asked for the workout, an NFL official said, "We can't tell you that," sources told ESPN.
Based on the lack of information, Kaepernick's team has begun to question the legitimacy of the workout, sources said. His reps have apparently asked the league office for a list of personnel executives that will be attending.
A source from an NFC team indicated to ESPN's Josina Anderson that their club would have "nothing to lose" by attending the workout. "I still think for us it would just be an information-gathering trip," the source added.
The Dallas Cowboys have expressed interest in attending as well, another source told Anderson.
Kaepernick became a polarizing figure in 2016 when he began kneeling during the U.S. national anthem before games to protest police brutality and social injustice. He hasn't played in an NFL contest since January 2017.
Reports surfaced in October that no franchise had offered the quarterback a contract or put him through private drills since he became a free agent in March 2017. At the time, Kaepernick's team said he had been "working out five days a week, for three years, in preparation to play again," according to Schefter.