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Sen. Marco Rubio, R-Fla., is set to make some high profile surrogate appearances on behalf of Mitt Romney next week in Colorado and Nevada, campaigning solo for the presumptive GOP nominee for the first time, ABC News has learned.

A source with knowledge of the events told ABC News Rubio will campaign for Romney at a rally at Rubio's old elementary school in Las Vegas, Nevada, Saturday followed by a rally in Denver, Colorado, later that day. Rubio also will participate in finance events for Romney while in the area.

Rubio, a dynamic young politician and emotional favorite of some conservatives to be the GOP running mate, endorsed Romney in March. But he has made limited appearances on the trail for Romney compared to other surrogates and potential running mates, such as former Minnesota Gov. Tim Pawlenty and Sen. Rob Portman, R-Ohio.

In April, Rubio appeared with Romney for the first and only time at an event in Aston, Penn. Earlier this month, Rubio headlined a fundraiser for Romney in downtown Boston. The Romney campaign invited Rubio to attend a donor retreat for Romney's top fundraisers, but the Florida senator declined to spend time with his family.

Rubio is the only person Romney has publicly acknowledged is being vetted for the vice presidential slot, but the Florida senator has stayed quiet on the process out of "respect" for Romney's decision.

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Though their time together has been sparse, Romney has incorporated Rubio into his stump speech several times, consistently drawing applause from crowds at the mention of the Florida senator's story.

"[Rubio] said something that will stay with me a long time," Romney said at a June rally in Council Bluffs, Iowa. "He said when I was a boy living poor in this country with my family, we saw some other homes, great big homes and fancy cars. He said, 'I never heard my parents say why can't we have what they have. Instead my parents said aren't we lucky to live in a country where with education and hard work, there's a shot we have of earning that ourselves.' That's the nature of America. We're the land of opportunity."

The son of Cuban immigrants, Rubio was born in Miami but his family moved to Las Vegas, Nevada for a brief time where his father worked as a bartender. While living in Nevada, the family, except for Rubio's father, converted to Mormonism.

Rubio wrote about attending C.C. Ronnow Elementary School, where Saturday's rally will take place, in his autobiography, " An American Son ."

"Veronica and I began our new life in earnest in September 1979, when we entered second and third grade at C.C. Ronnow Elementary School," Rubio wrote. "Our new school was only a few blocks from our house, close enough that we could walk there every day with the Thiriots and other neighborhood kids, while my mother trailed a few steps behind us. In Miami, our schoolmates had all been like us, the sons and daughters of Cuban exiles. But C.C. Ronnow had an ethnically diverse student body. We went to school with white, non-Hispanic kids like the Thiriots, with African-American students who were bused in from a neighborhood several miles away and with Hispanic children, mostly of Mexican descent, as well. At first, it was an unfamiliar environment, but one we quickly adapted to and enjoyed."