"Believe in something. Even if it means sacrificing everything", read a teaser for an ad Kaepernick tweeted.
"I think as far as sending a message, I think it's a bad message and a message that shouldn't be sent", Trump said.
Previously, The Wall Street Journal reported that, in depositions for Kaepernick's grievance, National Football League owners indicated that President Trump's attacks on the player protests pushed them to change the rules for the season just underway.
While the First Amendment gives these thugs the right to protest whatever they want, such outbursts of anger and violence are hardly productive.
Another Twitter user throws five pairs of sneakers into a fire pit to the tune of the national anthem playing in the background, all because Kaepernick is the "face of Nike" and "doesn't share the views of the people".
The Republican president is also a key figure in Kaepernick's grievance case against the league.
After the ad was tweeted by Nike Monday, many fired back, eviscerating the company for featuring Kaepernick.More news: Tom Brady Likes Colin Kaepernick Nike Advertisement On Instagram
Kaepernick hasn't played in the NFL since 2016 when he started protesting racial injustice during the national anthem.
"Especially proud to be a part of the Nike family today #justdoit", Serena Williams, 36, tweeted on September 3, the same day that Nike unveiled its new campaign celebrating the 30th anniversary of its "Just Do It" slogan.
Brushing aside the issue of racism, Trump attacked the protesting players past year, accusing them of showing "total disrespect of our heritage".
Kaepernick, who triggered a political firestorm after kneeling during the U.S. national anthem in 2016 to protest racial injustice, has not played in the NFL since early 2017.
The Nike campaign also promotes LeBron James, Serena Williams, NFL receiver Odell Beckham Jr. and Shaquem Griffin, a rookie linebacker for the Seattle Seahawks whose left hand was amputated when he was a child.
The world's richest sports league, the NFL distributed a record $8.1 billion to its teams last season and posted an estimated overall revenue of $14 billion.