Norwich confirmed the signing of defender Whittaker on a four-year deal, while Swiss club FC Sion landed striker Kyle Lafferty on a three-year deal.
Both players this week rejected a transfer to the newco Rangers.
Scotland international defender Whittaker announced on Sunday he would not be reporting back to Murray Park for training this week. And Northern Ireland international striker Lafferty followed suit, considering himself free to find a new club.
Norwich have announced the signing of 28-year-old Whittaker, subject to international clearance, becoming new manager Chris Hughton's first signing in the process.
Whittaker enjoyed a successful five years at Ibrox following a £2million move from Hibernian, winning Scottish Premier League titles, Scottish Cups and three Scottish League Cups.
"All of my experience to date has been in Scotland so I'm really looking forward to the challenge of playing in the Premier League," the 28-year-old Scotland defender told the Norwich website.
"When I spoke to (coach) Chris Hughton I was very impressed with his plans to progress Norwich City, and everyone I've spoken to in the game has had nothing but praise for the club."