"I believe in standing for the flag. To me, the flag represents the ideas and the ideals that make us America. I also believe in the freedoms the flag represents and that people can speak for themselves," Harbaugh said in a statement.
"I know this: Our players respect the flag and what it represents. And, we're all proud at the Ravens of the work they do to make this community and country better."
Harbaugh said in September that he supported his players' right to protest and that it was their choice how to express themselves during the national anthem.
"If I'm taking a knee, it's to pray," Harbaugh said at the time, via ESPN. "And I'll be praying for our country that we find a way to come together."
NFL owners unanimously approved the policy on Wednesday that requires players and league personnel on the sideline to stand for the national anthem but gives them the option to remain in the locker room if they desire.
The policy subjects teams to a fine if a player or any other personnel do not show respect for the anthem. Those clubs will also have the option to fine any team personnel for the infraction.
The anthem issue has been a divisive one, with some feeling players not standing for the song is disrespectful to, among others, the U.S. military. Others feel it is the players' right to protest perceived social injustice peacefully.
The change in policy comes after some players elected against standing for the national anthem.