In a gesture that organizers hope turns into an athlete-driven national movement, players from Georgia Tech, Georgia and Northwestern took the field Saturday with gear they had marked up to protest the NCAA's treatment of athletes on issues ranging from concussions to compensation.

ESPN cameras showed that players, including Georgia Tech quarterback Vad Lee, wrote on their wrist tape "APU" -- All Players United -- in a game against North Carolina.

In Georgia's game against North Texas, at least five Bulldogs offensive linemen joined the protest.

Georgia Tech QB Vad Lee wore "APU" on his wrist tape Saturday as part of the All Players United protest against the NCAA. Mike Zarrilli/Getty Images

Northwestern quarterback Kain Colter made the most visible and obvious display, writing "APU" in large white letters on black wrist tape.

No announcement was made before the game, and just after kickoff a statement about the effort was released through the National College Players Association, an advocacy group that supports NCAA reform.

Ramogi Huma, NCPA president, told "Outside the Lines" that the gesture was months in the making, with players from across the country having participated in weekly conference calls. He said high-profile players on other BCS teams that competed later Saturday have expressed interest in participating as well.

Huma said players plan to continue to use their visibility on nationally televised games to draw attention to the effort, associated with the social-media hashtags #APU and #AllPlayersUnited.

"Players will continue to wear the APU throughout the season and spread the word," Huma said. "They're taking the reform effort to television, which has never been done. They've been using their bodies to make money for the people who run NCAA sports. Now, for the first time, they're using their bodies to push for basic protections at the very least."

The NCAA said it supported debate in a statement released Saturday evening.

"As a higher education association, the NCAA supports open and civil debate regarding all aspects of college athletics," NCAA spokesperson Stacey Osburn said. "Student-athletes across all 23 sports provide an important voice in discussions as NCAA members offer academic and athletic opportunities to help the more than 450,000 student-athletes achieve their full potential."

The NCAA did not respond to a question asking if any NCAA rules prohibited the wearing the wrist slogans.

Lee, a sophomore, scrawled APU on his left wrist tape in black marker, as did backup quarterback Justin Thomas. Georgia Tech defensive end Jeremiah Attaochu wrote the acronym on his right wrist, and on a towel that hung from his waist.

Others, including junior running back Synjyn Days and defensive end Anthony Williams, marked up both wrists. From the television game feed, it was unclear how many players in total participated in the protest. None were immediately available for comment.

Kolton Houston, right, and at least four other Georgia linemen wore "APU" on their wrists Saturday. Cara Capuano/ESPN

Also wearing "APU" was Georgia junior offensive lineman Kolton Houston, who was forced to sit out the past three years because of a failed NCAA drug test. Houston was originally declared ineligible by the NCAA in January 2010, when he tested positive for a banned anabolic steroid that had been medically administered to Houston following a shoulder surgery he had while in high school. The ban was lifted in July after continued protests on his part that he was clean.

Joining Houston with "APU" on their wrists were his fellow linemen Kenarious Gates, Chris Burnette, John Theus and David Andrews.

Huma said that in all, players on at least four teams in four different BCS conferences have expressed interest in participating in nationally televised games Saturday.

The NCPAnow.org website described the "#AllPlayersUnited Campaign Goals" as:

• Demonstrate unity among college athletes and fans in favor of NCAA reform.

• Show support for players who joined concussion lawsuits against the NCAA, which could "force the NCAA to finally take meaningful steps to minimize brain trauma in contact sports and provide resources for current and former players suffering with brain injuries."

• Show support for the players who "stepped up in the O'Bannon v. NCAA, EA Sports lawsuit regarding the use of players' images/likeliness, which could unlock billions of dollars in resources for current, future, and former players."

• Stand behind individual players being "harmed by NCAA rules."

Huma said "this is a campaign designed by players that gets the issue in front of people in a way they're comfortable with." He said the primary concern of the players he is organizing is health and safety issues related to concussions.

The NCAA has come under fire from critics who contend the organization has not done enough to ensure that schools minimize the risk of concussions with players, by such measures as minimizing contact during practices.

The NCPA, which is supported by the U.S. Steelworkers union, is also asking in its statement that the NCAA direct "a portion of its over $1 billion in new TV revenue to guarantee basic protections."

Those include guaranteed scholarship renewals for permanently injured players, the promise that injured players will not have to pay sports-related medical bills, an increase in scholarship aid by $3,000 to $5,000 per year up to the cost of attendance, and the establishment of an educational "trust fund" that players could tap into after their eligibility expires.

Sonny Vaccaro, a longtime NCAA critic who has been involved in the O'Bannon lawsuit, called the coordinated public gesture unprecedented in college sports.

"No one has ever made the visible step -- no one," Vaccaro said. "They've all been afraid of their coaches. This was a major, major, major step forward. Eventually, I think some players will form (a union). They need the representation."

NCAA athletes are not treated as employees under current law. Asked if the NCPA has plans to challenge that notion, Huma said, "We've never advocated for creating a union. But the concussion issue is an example of what a union would do for players. NFL players get their health and safety protections from negotiated labor agreements."

ESPN's Cara Capuano contributed to this report.