At a press conference in West Palm Beach, Florida, Rubio admitted, "John Kasich has a better chance of winning Ohio than I do."
Rubio continued, "If a voter in Ohio is motivated by stopping Donald Trump and comes to the conclusion that John Kasich is the only one that can beat him there, then I expect that’s the decision they’ll make."
"I never talked to John Kasich about this," Rubio added.
Kasich's spokesman, Chris Schrimpf, said he "agrees with the Rubio campaign that the best chance to beat Donald Trump in Ohio is by voting for John Kasich, and in that spirit, Sen. Rubio should immediately tell his Super PAC to stop attacking the governor."
Kasich’s chief strategist John Weaver also touted the Florida senator's strategy on Twitter.
Rubio’s communications director Alex Conant backed up Rubio's argument earlier today.
“John Kasich is the one candidate in Ohio that can beat Donald Trump,” Conant said on CNN. “That’s stating the obvious. So if you're a Republican primary voter in Ohio and you don't want Donald Trump to be the nominee, John Kasich is your best bet.”
He also emphasized that GOP voters in Florida who don’t want Trump to be the nominee need to vote for Rubio. “If you want to defeat Donald Trump here in Florida, where there's 99 delegates at stake, you need to vote for Marco Rubio,” Conant said. “He’s the only one with a mathematical shot.”
Recent polling shows a tight race in Ohio between Kasich and Trump, while Trump holds a double-digit lead over Rubio in Florida polling.
Ohio and Florida hold their primaries on Tuesday, March 15.
ABC's BEN GITTLESON contributed to this report.