Dallas Cowboys quarterback Dak Prescott is reportedly dealing with a foot sprain, according to Dallas Morning News‘ Calvin Watkins. Concern sparked after a photo of the QB on vacation in Cabo, Mexico this week revealed he was wearing a walking boot on his right foot. According to Watkins’ source, Prescott has worn the boot for roughly a week, though it’s not known how he injured himself. The team’s last practice was on June 5. The photo that surfaced, which appears to have been taken at a marina, was posted on X by a user with the handle “elnarrador” and follows a report that the veteran QB is…