BOURBONNAIS, Ill. -- The Chicago Bears' final practice in Bourbonnais took a heated turn Sunday when head coach John Fox and right guard Kyle Long had to mediate a dispute between veterans Jeremiah Ratliff and Will Montgomery.

An incensed Ratliff had to be escorted to the sidelines after he took a swing at Montgomery during a team drill. No official reason was given as to why Ratliff lost his temper, but the soon-to-be 34-year-old defensive lineman seemed upset with some of Montgomery’s blocking methods.

Several members of the team tried to calm Ratliff down to no avail. Fox and Long later summoned Ratliff and Montgomery to the middle of the field during a water break in an attempt to diffuse the situation, but Ratliff did not appear to let it go.

Ratliff did return to the field following the incident, but the Bears held him out of the final live goal-line period.

“We made it very, very competitive,” Fox said. “This was not one of those non-padded, easy, exit final days of camp. We kind of warned them and alerted them. Stuff happens in camp.

“Sometimes things start early in practice. I wasn’t at the drill. That needs to be communicated to me better. I haven’t been in a camp where we didn’t have that, ever, in 26 years.”

Outside linebacker Jared Allen said he wasn’t surprised by the flare-up.

“Every time you go full pads on the last day of camp this stuff happens,” Allen said.

In other practice news, Sunday marked the return of second-year quarterback David Fales, whom the team officially removed from the non-football injury (NFI) list. Fales had battled an undisclosed illness since the beginning of camp.

“The medical people thought he was ready,” Fox said. “They thought he had healed good enough to go out and do physical activities. He’s been doing some of that with the trainers on the sideline. To my knowledge right now, he got through it pretty good.”

Wide receiver Alshon Jeffery, tight end Chris Pantale (illness), offensive tackle Jason Weaver and Long (coaches’ decision) did not participate in Sunday's practice. Running back Daniel Thomas was limited due to a knee injury.