Haley, the 44-year-old South Carolina governor, had earlier endorsed and campaigned for Senator Rubio, who dropped out of the race on Tuesday after suffering a humiliating defeat at the hands of Trump in his home state of Florida.
Haley, who has not yet made an official announcement to endorse 45-year-old Cruz, told reporters that she hoped that the Senator would emerge as the Republican presidential nominee.
"The only thing I can say now is my hope and my prayer is that Senator Cruz can come through this. That's who, privately, I am fighting for," Haley said.
Cruz is currently lagging far behind front runner Trump in the delegate count and unlikely to cross the half way path of 1237 delegates but Haley thinks otherwise.
"I do see a path for (Cruz), because I think he's been solid and strong the entire way. I think that he has been disciplined in the way that he has done it," the popular Indian American Governor said.
Meanwhile, Trump is considering his trusted military advisor Lt Gen (rtd) Michael Flynn as his national security advisor, the reports said.
Flynn, 56, was one of the top military leaders to have endorsed Trump and has been his closest military advisor for more than a year now.
"Lieutenant General (rtd) Michael Flynn has emerged as Donald Trump's leading candidate for national security adviser, according to people familiar with the president- elect's transition planning," National Review reported yesterday.
If selected, he would succeed Susan Rice as the National Security Advisor.
"Like the president-elect, Flynn, a self-described "maverick" and longtime Democrat, shares a penchant for unvarnished straight talk that has earned him praise from some and condemnation from others," Review said.
He served as the director of the Defence Intelligence Agency, commander of the Joint Functional Component Command for Intelligence, Surveillance and Reconnaissance, and chair of the Military Intelligence Board.