Republican front-runner Donald Trump mentioned Sonnenfeld, also a CNBC contributor, during Wednesday night's debate in an exchange with the former Hewlett-Packard CEO over their business records. Trump cited comments from a column in Fortune in which Sonnenfeld articulated Fiorina's failings as a CEO.
"HP was in great shape when [Fiorina] got there and she left it in tatters," Sonnenfeld told CNBC's Squawk on the Street on Thursday.
"She's never gotten a CEO job tenure since. What does that tell you?" he added. "In 10 years, what has she learned?"
Sonnenfeld has echoed similar concerns in the past but this time added he believes Fiorina deserves a chance to prove herself.
"The comeback stories are very much the American dream but her comeback can't be from failure to the American presidency as the commander in chief of the free world when she hasn't proven herself," Sonnenfeld told CNBC.
"I don't know why in 10 years no board of directors anywhere in the world has given her that chance," he said. "Trump, he's come back from his setbacks."
According to Fiorina's campaign website, she's already proven herself as a leader.
The website says Fiorina was the first woman to lead a Fortune 50 business and expanded HP from the 28th largest company in the United States into the the 11th largest. The campaign added that under her leadership, HP saw revenue doubled, tripled the rate of innovation, more than quadrupled its growth rate and quadrupled its cash flow.
When asked if HP's latest job cuts might be linked to Fiorina's leadership, Sonnenfeld said the company actually lost its footing under her reign as CEO. Fiorina's last-minute decision to buy Compaq after competitor IBM purchased PricewaterhouseCoopers consulting put HP into a devices business, which it is now restructuring.
Sonnenfeld said, "It took them in the wrong direction."