Speaking at last month's Glamour "Women of the Year Awards," the USWNT star declared her support and solidarity for the former San Francisco 49er quarterback.
Kaepernick hasn't played for an NFL team since 2016 after sparking a wave of protests about social and racial injustice by kneeling during the national anthem at games.
Rapinoe, who scooped Glamour's women of the year award for her achievements on and off the field, commended the 31-year-old for his sacrifice: ''We still have Colin Kaepernick, who is not playing and I did the same thing that he did in kneeling.
"So shout out to Colin Kaepernick and everything that he does,'' she added.
Kaepernick's three-year hiatus could come to end on Saturday when he auditions for NFL teams in a private workout arranged by the league.