Sources: Wes Welker likely out

Denver Broncos wide receiver Wes Welker is making progress in the NFL's concussion protocol, but is still expected to be ruled out for Sunday's game against the Houston Texans, sources told ESPN.com's Jeff Legwold.

Fox Sports reported Thursday night that Welker would miss his second straight game.

Welker did not participate in Thursday's practice but spent some of the workout in the Broncos' weight room. Broncos coach John Fox said Welker also did some on-field work outside as well.

Welker, who suffered a concussion just before halftime of the Broncos' win against the Tennessee Titans, was held out of last Thursday's loss to the San Diego Chargers.

Welker also suffered a concussion in the Broncos' win Nov. 17 against the Kansas City Chiefs.

Welker, 32, has 73 receptions for 778 yards and 10 touchdowns in 13 games this season.

Information from ESPN.com Broncos reporter Jeff Legwold was used in this report.