McKeon exited Friday's preseason game against the Cardinals due to an ankle injury, Michael Gehlken of The Dallas Morning News reports.
McKeon was impressing early in training camp and was putting together a strong case for a spot on the 53-man roster. The 23-year-old hauled in two of his four targets for 26 yards in last week's Hall of Fame Game against the Steelers before he secured his lone target for eight yards early in Friday's matchup. McKeon required a cart to get to the locker room after he left the game in the second quarter, and it's not yet clear how much time he'll miss due to the injury.