Heisman Trophy-winning quarterback Johnny Manziel can't capitalize on his name, but he can protect it.

Manziel's corporation, JMAN2 Enterprises, filed a lawsuit in Texas last week against Eric Vaughan, a man who was selling T-shirts that read, "Keep Calm and Johnny Football." Manziel claims Vaughan infringed on his trademark rights.

Although Manziel didn't file papers to the U.S. Patent and Trademark Office for "Johnny Football" until Feb. 2, a trademark doesn't have to be federally registered for there to be an ownership claim.

The lawsuit asks the court to award damages for the unlawful sale of the "Johnny Football" T-shirts. Texas A&M's compliance office recently received a ruling from the NCAA that a student-athlete can keep financial earnings as a result of a legal action.

Common law trademark rights apply until the formal registration process is complete. Manziel doesn't automatically own the trademark, but it will be hard to argue that products that have recently been produced, including Vaughan's, don't refer to the Texas A&M quarterback.

The corporation set up for Manziel in December cannot capitalize off the quarterback until his NCAA eligibility has expired or he leaves after next season to go into the NFL draft, but can take action to further its claim of ownership of "Johnny Football."

The address listed for JMAN2 Enterprises is the office of Manziel Interests, a business run by his father that focuses on oil, real estate and other investments in Tyler, Texas.

"Manziel's attorneys and Texas A&M regularly communicate on legal issues where we have joint interests," said Shane Hinckley, assistant vice president of business at Texas A&M. "This usually means that our trademarks are being used in conjunction with Johnny Football. We are pursuing our own legal interests separately, but stay in contact due to the nature of the relationship."

Hinckley said the school is not providing legal or financial support for any issues outside of issues that involve Texas A&M trademarks, although the school and Manziel's attorneys could work together to take further action if aggressive businesses don't stop after being sent a cease-and-desist letter.

Per NCAA rules, the school cannot use Manziel's name on products it sells, including jerseys and T-shirts. Texas A&M can use Manziel on promotions and on editorial business, such as on game programs.

Manziel's trademark application for "Johnny Football" says he plans to use the phrase on everything from athletic apparel to motivational and educational speeches. Manziel's filing says his name tied to "Johnny Football" was first used in business connected to him this past fall.

News of the lawsuit was earlier reported by The Southeast Texas Record, a legal journal.

Manziel said this past week that he would be taking his classes online in the spring due to his celebrity on the Texas A&M campus.