7:14 AM ET

According to sources, Colin Kaepernick stood out in his workout with the Las Vegas Raiders, but no signing was imminent as of late Thursday night.

A source said that the Raiders considered the workout positive. Las Vegas could be looking for another passer to serve as the backup for Carr despite trading for a former New England quarterback and signing another.

Quarterbacks usually throw the route tree on air, implement team-specific offensive principles on the field and meet with their coaches in team workouts. Team workouts are less scripted than the player-organized workouts that Colin Kaepernick has done in the past to showcase his talents to NFL teams.

Since 2016 when he began protesting racial inequality during the national anthem, Colin Kapernick hasn't played in the NFL. The Seattle Seahawks brought him in for a visit in May of last year.

Jim Harbaugh, the former coach of the San Francisco 49ers, invited Colin Kaepernick to throw out the ceremonial first pitch at the Michigan spring game.

Mick Lombardi was a 49ers assistant from 2013 to 2016 and is a possible link to Kaepernick.