The wide receiver missed the final seven games of the 2009 season after suffering a knee injury.
Spagnuolo talked about Burton the day after the Ravens game.
"Keenan is a pro," Spagnuolo said. "He is what you want all your guys to be like on and off the field and in the meeting rooms and with the other players. Now, he's had to battle some injuries, but he's done it. That tells you a lot about the character of that guy.