"I need to provide for my family, and I had to make the call."
Whittaker had been training hard for the event and was excited about the prospect of being able to represent his country. However, stepping away allowed him to put all his focus on his return to the octagon where he'll meet Cuban Yoel Romero.
Romero was the man Whittaker beat to win the middleweight title. The two met in 2017 to determine an interim title holder while Georges St-Pierre was out due to illness. He was forced to vacate the title, and Whittaker was promoted to undisputed middleweight champion.
The 27-year-old will face his first defence as champion when he meets Romero in June for the second time. Winning by decision in their last encounter, Whittaker was hoping he wouldn't have to leave next month's fight up to the judges.
Whittaker's striking power has been well displayed in his time with the UFC, with knockout wins over the likes of Ronaldo Souza, Derek Brunson and Brad Tavares.
In comparison, Romero also beat Brunson by knockout but needed to go to the scorecards to get the result against Souza and Tavares.