Sources: Wes Welker mulling retirement after 12 NFL seasons

Peyton Manning isn't the only Denver Broncos player pondering his NFL future. Wes Welker is also undecided on the matter.

The 33-year-old wide receiver, who is slated to become a free agent next month, is considering retirement after several years of head injuries and declining production, sources have told FOX Sports.

One of the sources said no final decision has been made, though Welker has told concerned friends, family members and associates he's at least giving serious thought to walking away.

Welker has mulled the issue in recent weeks after telling reporters in the immediate wake of the divisional-round loss to the Indianapolis Colts he was "not even thinking about that right now." One day later, as he and his Broncos teammates were cleaning out their lockers, Welker was asked about returning to Denver and replied, "I don't know. There are a lot of things I've got to figure out in the offseason."

Welker had a total of 122 catches for 1,242 yards and 12 touchdowns in two regular seasons with the Broncos, though his reception total dropped from 73 in 2013 to 49 in 2014 and he had only two touchdowns this past season. Welker also suffered a concussion in the preseason -- the third documented concussion during his time in Denver.

If Welker retires, he'll do so having put together an outstanding career for an undersized free agent. The 5-foot-9, 185-pounder has 890 career catches for 9,822 yards. He had five 100-catch seasons with the New England Patriots before heading to Denver to join Manning.

The Broncos are awaiting Manning's final decision. The Times-Picayune reported Manning is training in New Orleans with the intention of returning, though sources have told FOX Sports that Manning has yet to inform the team of his final decision. Manning is slated to meet with general manager John Elway and team president and CEO Joe Ellis before next week's scouting combine in Indianapolis.