Callahan is taking a trip to Denver, Ryan O’Halloran of The Denver Post reports.
Callahan played for Vic Fangio in Chicago.
Callahan, 27, spent his first four seasons with the Bears. He appeared in 45 games with 29 starts since signing with Chicago as an undrafted free agent.
In his career, Callahan has made 122 tackles, four interceptions, 20 pass breakups and four sacks. He played 13 games with 10 starts last season, recording 45 tackles, two sacks and two interceptions.