Isaiah J. Kacyvenski (/ˌkæzəˈvɪnski/ KAZ-ə-VIN-skee; born October 3, 1977) is a former American football linebacker of the National Football League. He was drafted by the Seattle Seahawks in the fourth round of the 2000 NFL Draft. He played college football at Harvard and earned an MBA from Harvard Business School after he retired. Kacyvenski also spent time with the St. Louis Rams and Oakland Raiders. After spending the 2007 season out of football trying to return from microfracture surgery, Kacyvenski officially announced his retirement in 2008.