(NEXSTAR) – Despite experiencing atrial fibrillation just a few days ago, and having his “heart shocked back into rhythm,” Arizona Cardinals defensive end J.J. Watt says he’ll be playing in Sunday afternoon’s game against the Carolina Panthers.

In a Sunday morning tweet, the Wisconsin native said, “I went into A-Fib on Wednesday, had my heart shocked back into rhythm on Thursday and I’m playing today. That’s it.”

He noted that he had learned someone “leaked some personal information about me” and that the information was going to be reported Sunday.

Atrial fibrillation, otherwise known as AFib, is a heart arrhythmia that occurs when the heart beats too slow, too fast, or irregularly, according to the Centers for Disease Control and Prevention. It can increase a person’s risk of having a stroke, and was determined to be the underlying cause of more than 26,000 deaths in the U.S. in 2019.

Watt missed practice Wednesday and Thursday. According to ESPN, the Cardinals listed his absence as the result of “calf/illness” on their injury report.

The 33-year-old was not feeling well Wednesday and visited a doctor, NFL Network’s Ian Rapoport reported. When the doctor determined Watt’s heart wasn’t in rhythm, Watt underwent the shock treatment.

AFib can usually be treated with medications, blood thinners, surgery, and healthy lifestyle changes, the CDC explains.

Watt is in his second season with the Cardinals after spending 10 seasons with the Houston Texans. He and wife Kealia Ohai, a professional soccer player with the Chicago Red Stars, are expecting their first child.