He had been cleared by team doctors.
"I had a good amount of nerves," he told reporters. "If you haven't done something in a long time, you always have some nerves the first time back. I had some good reads and had some bad reads. All of that comes with (this) being the first day (back)."
Bruschi had an interception in the Patriots' 24-21 victory over Philadelphia in Super Bowl XXXIX on Feb. 6. He suffered what was termed a "mild" stroke on Feb. 16 and subsequently underwent heart surgery.
The nine-year veteran saw a number of doctors to gather information to see if a comeback this season was possible.
"First of all, I just have confidence in my doctors and what they've told me. Everyone has been positive about what I can do and has been clear about it."