Matthews shared a photo Wednesday on Instagram of the cleats he will against Houston.
The cleats say "Know Your Rights Camp" on each shoe along with the quarterback's name and Kaepernick kneeling on the right toe.
The wide receiver, who was not in the locker room to talk with the media on Wednesday, wrote on Instagram he doesn't have a foundation. Matthews wrote he's supporting Kaepernick for his sacrifice bringing attention to everyday issues along with the quarterback's foundation because everyone should know their rights and use them.
Matthews has stayed off the field during the anthem in protest, though he stood Nov. 12 to honor veterans