To stay in the race to the White House both Rubio, 44, and Kasich, 63, need to win the primaries in their respective states, which would likely propel Trump closer to bagging the party's presidential nomination for the November 8 elections.
The events tomorrow has been dubbed "Super Tuesday 2.0", when five states will go to the polls including Florida, Illinois, Missouri, North Carolina and Ohio as well as the Northern Mariana Islands.
In Ohio, its popular governor Kasich is in a tight race with Trump, latest opinion polls said yesterday.
To give a boost to his campaign, the former Republican presidential nominee Mitt Romney has announced that he would campaign in favour of Kasich in Ohio.
The strategy for Romney, who has openly called for defeat of Trump, is to prevent the outspoken New Yorker from winning the majority of the delegates so that the final decision on the nomination is taken at the Cleveland convention in July.
In order to seal the deal, Trump desperately needs to win both Florida and Ohio -- which are winner-takes-all states.
Rubio with three wins has 163 delegates, while Kasich who
is yet to win a single state has 63 delegates. To win the party's presidential nominee, the candidates need to have the support of 1,237 delegates out of a total of 2,472 delegates.
Joining Romney's strategy, Rubio has also asked his supporters to vote for Kasich in Ohio.
"If we reach a point in this country where we can't have a debate about politics without it getting to levels of violence and anger," he told CNN, "we're going to lose our republic."
However, in his own home state of Florida Rubio is fighting the toughest political battle of his life.
Despite having pitched his tent in the state for the past one week, Rubio is trailing behind Trump with a double digit margin.
With stakes high in Ohio, Trump launched his characteristic personal attack on Kasich alleging that he has been absent from the state for long.
"Trump is lying to Ohioans, and we are consulting with our lawyers on our next steps. We are 100 per cent certain that John Kasich will be on the ballot in Pennsylvania," said Rob Nichols, spokesman for John Kasich.
"Trump's dishonest tweets and robocalls means his team either knows nothing about Pennsylvania election law or he's just scared to death we're going to beat him. Donald Trump continues to play gutter politics, America deserves better and he owes Ohioans an apology for lying to them," Nichols said.
