Denver Broncos wide receiver Wes Welker is not expected to play Thursday night against the San Diego Chargers because he sustained his second concussion in the last four games.
Because of the NFL's testing protocol for concussions, Welker will not be cleared in time.
Welker was injured in the second quarter of Sunday's win over the Tennessee Titans when he was hit hard by safety Bernard Pollard. He finished with five catches for 61 yards and a touchdown.
Welker also had a concussion Nov. 17 against the Kansas City Chiefs.
This season, Welker has 73 catches for 778 yards with 10 touchdowns.