MANCHESTER, N.H. — Sen. Marco Rubio, R-Fla., on Thursday rejected Chris Christie's taunt that he's a "bubble boy," and said Christie's comments is a sign that desperation is setting in for the New Jersey governor.

Christie has repeatedly attacked Rubio on the campaign trail in New Hampshire for being an inexperienced one-term senator whose speeches are written by handlers.

"Let's get the boy in the bubble out of the bubble and let's see him play for the next week in New Hampshire. I'm ready to play. I hope he is because I'll be ready to see him on stage on Saturday night," Christie recently told New Hampshire voters.

As new polls show a close race for second place emerging in the Granite State, Rubio feels Christie's criticism is silly.

"When people are having a tough time in a campaign, especially near the end, you see some desperation set in they start saying things," Rubio told reporters Thursday.

Rubio, who ranks second in the Washington Examiner's power rankings, also said it was unfair to criticize former Sen. Rick Santorum, R-Pa., for struggling to identify any of the Florida senator's accomplishments. Santorum endorsed Rubio Wednesday.

"Let's be fair to Rick, he spent the better part of the last year and a half running his own campaign. He just endorsed last night so I wouldn't expect him to be entirely familiar with my record," said Rubio.