The team made the move two days before it opens training camp and there's a chance Welker could come off the list by then and take part in drills. If he stays on it, it could allow other receivers trying to make the team more opportunities in practice.
Welker had surgery in February after tearing the anterior cruciate ligament in his left knee on the fourth offensive play of a 34-27 loss at Houston in the regular-season finale. He also damaged his medial collateral ligament, which didn't require surgery, on the play when he planted his left leg after making his NFL-leading 123rd catch of the season.
Welker missed the Patriots only playoff game, a 33-14 loss at home to the Baltimore Ravens in which New England trailed 24-0 in the first quarter.
But exactly four months after undergoing surgery, he took part in agility drills and caught passes while wearing a brace on his knee during the team's organized team activities on June 2.
"I didn't think it'd be that big a deal," Welker said after a similar session five days later. "I've been pushing it and trying to get ready and get out there with my teammates, get a few reps and try and get better as much as we can."
On Tuesday, the Patriots also placed linebacker Shawn Crable, a third-round draft pick in 2008, and rookie defensive lineman Kade Weston, a seventh-round pick, on the active physically unable to perform list.
A player cannot go on that list once he practices. If a player is put on a different list — the reserve physically unable to perform list — he must miss a minimum of the first six weeks of the regular season.
Without Welker, whose 346 receptions during the past three seasons were the most in the NFL, the Patriots used rookie Julian Edelman in his slot receiver spot in the playoff game. Randy Moss is the other starting wide receiver.
In the offseason, New England signed free agent wide receivers Torry Holt, who had 51 catches with Jacksonville last season, and David Patten, who played for the Patriots from 2001 through 2004 but sat out the 2009 season after being released by Cleveland during training camp.