Just when former Tennessee DE Derek Barnett was starting to get the hang of the NFL, the Philadelphia Eagles’ first-round pick will now have to miss some time because of an injury.

According to Pro Football Talk, Barnett has a “lower body injury” and coach Doug Pederson said the star pass rusher is day-to-day.

In two preseason games, Barnett has been impressive, racking up three sacks in his limited action.

He was set to earn some time with the starting defense in the Eagles’ third preseason game against the Miami Dolphins next week, but those plans may change depending on how much time he misses.