Welker, who served two games of his original four-game suspension, practiced fully Wednesday, Thursday and Friday as the team worked him more and more into team drills as the week wore on.
Coach John Fox said Welker was probable for Sunday's Super Bowl rematch in Seattle.
"It's been great," Fox said of Welker's work this week. "He's a veteran guy that attacks preparation, and he's had a great week.''
Welker was originally suspended four games for violating the league's policy on performance-enhancing drugs. However, when the league and the NFL Players Association agreed to a new drug policy this week, it changed the guidelines for Welker's suspension and he and several other players were reinstated.
The wideout is expected to be in the Broncos' rotation Sunday, but since he's also still returning from a concussion suffered in the preseason, he may not see the number of snaps in the game he would have if he had practiced more before the suspension.
Wednesday was Welker's first appearance on the practice field since Labor Day, when he was only a limited participant under the guidelines of the league's concussion protocol.
Welker, who suffered a concussion in the Broncos' Aug. 23 preseason game against the Houston Texans, said he had been cleared medically within the past week.
"I feel great; I feel sharp,'' Welker said earlier this week.