The Indianapolis Colts are awaiting MRI results on Bob Sanders' injured elbow, but the veteran safety was able to do limited work in practice Monday while reporters were present.
Sanders missed all but two games last season with knee and biceps injuries and all but six games in 2008 with other injuries.
Sanders now has played in 48 career games and missed 49 -- a number that could increase if the elbow injury is season-ending.
"Well, that's all speculation right now," Caldwell said. "He has an MRI sometime today; he has not had it as of yet. There will be some type of prognosis at that time."
The Associated Press contributed to this report