Eric Fisher has sustained a shoulder injury which could force him to miss the Kansas City Chiefs' pre-season game against the San Francisco 49ers next week.
The top pick from this year's draft suffered a bruised muscle during the AFC West side's defeat to the New Orleans Saints on Friday.
Head coach Andy Reid told The AP: "He can't quite get the motion he needs, but again, it's not structural.
"It's a muscle bruise. We'll just get it settled down and see where it goes. It's day to day."
The tackle signed a four-year contract worth $22.1m (£14.2m) with a $14.5m (£9.3m) signing bonus last month.