Rumors about the endorsement deal first surfaced after Romo put a pair of Under Armour cleats on display in his locker while speaking to media members this off-season. Since the start of training camp, Romo has worn Under Armour apparel, including the brand's cleats and hats.
In the past, Romo has worn Nike cleats while playing, but has painted over the logo when doing so.
Under Armour signed a 10-year contract with Romo's friend and fellow-Dallas resident Jordan Spieth in January. Spieth has since won The Masters and the U.S. Open in 2015.
Romo had been an endorsement free agent since 2013, when his contract with Starter expired.
- Kayla Lombardo