PITTSFORD, N.Y. -- Buffalo Bills defensive end Mario Williams left the team's training camp at St. John Fisher College on Monday to be evaluated by doctors off-campus, according to head coach Doug Marrone.
"I have not heard any report back," Marrone said at a news conference Monday.
Williams recently told trainers that his foot was sore and watched the Bills' first training camp practice on Sunday evening from the sideline.
"We were all ready to go," Marrone said. "It happens. You go out there for the first time. Sometimes you're sore."
Marrone said he did not know how Williams was injured.
"When you have soreness, you can't pinpoint it to a certain time," Marrone said. "I wake up sore every day."
Other than safety Jairus Byrd, who has yet to sign his franchise tender, Williams was the only Bills player not on the practice field for Monday's session.
"We've been fortunate, these last two days," Marrone said. "We've come out healthy."