ENGLEWOOD, Colo. — Denver Broncos cornerback Bryce Callahan, who was one of the team’s primary targets in free agency with a three-year, $21 million deal, will miss at least “four to six more weeks” because of a troublesome left foot injury, and both surgery and a trip to injured reserve are still under consideration.

Callahan has struggled with a screw in his surgically repaired left foot — he suffered a fracture with the Chicago Bears last December — and underwent what Broncos coach Vic Fangio described as a non-surgical procedure Wednesday. Fangio also said Callahan visited the surgeons this past weekend who performed his December surgery to repair the original fracture.

The fifth-year cornerback left a July practice at the downtown stadium due to pain in the foot, did not play in the preseason and has not played in the Broncos’ first three regular-season games.

“He’s going to be out at least four to six more weeks,” Broncos coach Vic Fangio said Wednesday. ” … He’s still having complications from the injury he had last year and the surgery he had after the injury.”

Asked to expand on the “procedure,” Fangio added: “It’s not an operation — that was the best word I was told to describe it. It’s more to promote the healing.”

Asked if going on injured reserve is still a consideration, Fangio said: “It was and still is.” And when asked if surgery was still an option, Fangio added “I’m sure it is, if nothing gets better.”

Last week when Fangio was asked if more time was needed for pain to subside in Callahan’s foot or if Callahan needed more conditioning before he could return to practice, Fangio said “Yeah (pain) is a big part of it, yes.”

Callahan’s absence has forced the Broncos to significantly alter their preseason plan on defense. Kareem Jackson has had to move from safety to play the nickel cornerback spot, while Chris Harris Jr., who was going to be the nickel cornerback, has played on the outside.

The Broncos have also tried both Isaac Yiadom and De’Vante Bausby at cornerback in the starting defense as Bausby, who played 41 snaps against the Packers this past Sunday and broke up two passes, is expected to start Sunday against the Jacksonville Jaguars.