Colts Coach Chuck Pagano told reporters Collie suffered his latest concussion during Sunday's pre-season contest against the Pittsburgh Steelers.
"He came in today, felt really good, was examined by the doctors and basically is going to be day-to-day," Pagano said. "He felt really good coming out of the game this morning after being evaluated today."
The receiver was hit in the helmet by the forearm of Pittsburgh's Larry Foote after catching an Andrew Luck pass over the middle.
Collie suffered a pair of concussions during the 2010 season, including an incident in a game against Philadelphia in which he lay on the field for almost 10 minutes before being carried off on a stretcher. One week later, he left a game against New England with concussion-like symptoms, The Indianapolis Star reported.