Tom Brady texted an apology to Tyrann Mathieu for several on-field verbal altercations, according to a source with knowledge of the situation.

Brady apologized to Mathieu for losing his composure in the heat of the moment, of which Mathieu said, "I've never really seen that side of him."

Brady and Mathieu sparred multiple times with Brady even chasing him down one time. 

Brady called Mathieu the "ultimate competitor" in his apology text and said he knew he needed to match Mathieu's intensity Sunday.

Mathieu explained his side of the altercation, saying in a since-deleted tweet that Brady started the verbal spat when he called Mathieu "something I won't repeat."

"He's clearly chasing me, but I got flagged," Mathieu said in another deleted tweet.