Kaepernick, 31, hasn't appeared in an NFL game since 2016. Meanwhile, Tebow, 31, is in pursuit of reaching the major leagues.
The Alliance of American Football reportedly reached out to former NFL starting quarterbacks Colin Kaepernick and Tim Tebow, but was turned down by both, according to The Athletic's Lindsay Jones.
AAF co-founder Bill Polian told Jones that league CEO Charlie Ebersol contacted Kaepernick to gauge his interest in playing. "I don't know what transpired, but he's obviously not playing," Polian said.
Kaepernick reportedly wanted $20 million or more to consider joining the league, per the Associated Press.
Kaepernick hasn't appeared in an NFL game since 2016. The former 49er quarterback began protesting police brutality and racial inequality by kneeling during the national anthem that season, and has gone unsigned each of the past two offseasons.
Polian told Jones that he contacted Tebow directly, but the former Heisman Trophy winner declined. Tebow told the AAF that he wanted to continue pursuing his baseball career.
Tebow was one of 13 minor players within the New York Mets system invited to participate with the major league club during spring training. He last appeared in an NFL game in 2012.