Stewart made a visit with the Colts earlier this week, Ian Rapoport of NFL Network reports.
The former Pro Bowl safety has been out of work since being cut by Denver on March 6. With one of the Colts' projected starting safeties (Clayton Geathers) still recovering from minor knee surgery, Stewart would provide a quality insurance option in the event Geathers' rehab lingers into training camp or the regular season. Stewart, 30, is coming off a 60-tackle, two-interception season.