The 6-foot-2, 213-pound Aiken last week was released from the practice squad of the Buffalo Bills.
The Bears released Harvey Unga as the coresponding move.
There's a chance the team could promote rookie Joe Anderson from the practice squad to the active roster, and move Aiken into his place, which would seem a likely scenario. Anderson turned heads in the
preseason and has some familiarity with the offense, despite his inexperience.
Offensive coordinator Mike Tice lamented the loss of Jeffery, but expects the team to pick up the slack with players such as Earl Bennett, who is expected next week to make his return after missing the last two games with a hand injury.
"I don't know how long he's out, but it's tough," Tice said. "Hopefully we get Earl back. This is the NFL, and as you well know we have injuries. This is one that's too bad because he was starting to come on; great rapport between he and (quarterback) Jay (Cutler). But hopefully we can get Earl back and just keep going."
A second-round pick, Jeffery caught 14 passes for 184 yards over the first five games before suffering the hand injury during the second half of Chicago's 41-3 pummeling of the Jacksonville Jaguars. Jeffery underwent an x-ray on Monday, and it was determined he suffered a fracture in the hand, according to a source, who disclosed the receiver was wearing a cast and that the injury wouldn't require surgery.
Jeffery's timeline for a return is unknown, but a source said he'd miss "a few weeks," including the bye week in that timeline.
"It's tough," Bears coach Lovie Smith said. "But you know, we know we're going to get him back. Injuries are part of it. He'll be back before long."
Because Jeffery kept his hands in the pocket of a gray sweatshirt during the portion of practice in which the media is allowed to view, it was also unknown whether the receiver was wearing a cast.
It's likely that Jeffery's repetitions in the coming games will be divvied up between Bennett and Devin Hester, who expressed frustration with his role in the offense recently, but scored his first touchdown of the season on Oct. 1 in the team's win over the Dallas Cowboys.
Aiken, meanwhile, has NFL experience, having played in two games, contributing primarily as a special teamer. Signed as an undrafted free agent in 2011 by Buffalo from Central Florida, Aiken has spent the majority of his time in the league on the Bills' practice squad. So his lack of familiarity with Chicago's offense could mean the team plans to proceed slowly with the new receiver.
Aiken worked out for the Green Bay Packers on Monday, and was scheduled Tuesday to visit the New England Patriots, according to a source. As Aiken boarded a flight leaving Green Bay, the Bears swooped in with a call, and the receiver immediately proceeded late Monday afternoon to Halas Hall.
In other injury news, Julius Peppers (foot) didn't participate in Tuesday's brief one-hour session, but should be available when the team returns for an Oct. 22 matchup with the Detroit Lions along with Brian Urlacher, who will continue to be held out sporadically as he continues to work himself back to form. Roberto Garza appeared to be a non-participant in Tuesday's workout, but the reason is unknown. Because the team doesn't play a game this week, it isn't required to release injury information.
Evan Rodriguez, meanwhile, also missed as he continues to recover from a sprained knee.