Coach Doug Pederson said Shatley reported an issue after Wednesday's practice and got immediate treatment. He was held out of Thursday's practice but was back in full uniform for Saturday's practice at EverBank Stadium. Pederson said he would be limited until he receives full medical clearance.
"Everything's calmed down," Pederson said. "From a health standpoint, he's good."
Atrial fibrillation is an abnormal heartbeat caused by fast and irregular beats from the upper chambers of the heart, according to Johns Hopkins medicine's website.
Shatley started 12 games at left guard in 2022 and was working with the first-team offensive line in training camp. He's entering his 10th season, which makes him the longest-tenured Jaguar on the roster.
Cornerback Tyson Campbell suffered a concussion during Saturday's practice after a collision with receiver Christian Kirk during 11-on-11. Campbell spent several moments on the ground before walking off the field unassisted. He went into the locker room and the team said he is now in the concussion protocol.
Also, kicker Brandon McManus missed Saturday's practice because he was in Canton, Ohio, for the Pro Football Hall of Fame induction ceremony in support of former teammate DeMarcus Ware.