Mitt Romney's campaign has begun prepping the presumptive GOP nominee for this fall's presidential debates, according to a report in the New York Daily News.

Romney team sources told the paper that the former Massachusetts governor worked through two rounds of "debate prep" during his retreat held with GOP advisers and donors last month in Part City, Utah.

The report says Romney was joined by six to eight campaign aides who helped the candidate review numerous topics they believe likely to appear in the three debates with President Obama in the run up to the November general election. 

Aides worked to develop "test responses" to questions they believe Romney will be asked, according to sources. 

However, the paper reports that "podium practices" with a stand-in for President Obama will not happen until much later in the process, namely because Romney places low value on their preparation value.

“There will be some role-playing but not as much as other Presidential candidates... The traditional model doesn’t fit his style,” the Daily News quoted an unnamed Romney adviser as saying. 

Aides say Romney has settled on his stand-in for Obama during those mock debate sessions, but will not reveal that pick soon. 

Some sources say GOP Sen. Rob PortmanRob PortmanGOP senators bristle at Trump's Medicaid cuts Overnight Energy: Trump budget takes flak over oil provisions GOP senators knock Trump's budget proposal MORE, also rumored to be on Romney's short-list for vice president, is under consideration as a debate proxy for Obama. 

Portman would have experience in that role. He played Obama for Sen. John McCainJohn McCainRepublicans give Trump's budget the cold shoulder Overnight Defense: Trump budget gets thumbs down from hawks | UK raises threat level after Manchester attack | Paul to force vote on 0B Saudi arms deal Five takeaways from a busy day of Russia hearings MORE during the Arizona lawmaker's 2008 presidential bid and helped prep former President George W. Bush during his 2004 race against Sen. John KerryJohn KerryColombia's president is a foreign guest Trump should listen to Anti-ISIS cyber op struggled with issue of notifying allies How American compassion, vision and innovation can end the AIDS epidemic MORE (D-Mass.).

The Obama campaign has already tapped Kerry to play Romney during three mock debate rehearsals they plan to hold later this year, campaign officials confirmed last month to The Hill. 

Obama and Romney are scheduled to square off in three debates, the first of which will be held in Denver on Oct. 3.

Two more debates will take place at Long Island's Hofstra University on Oct. 16 and in Boca Raton, Fla. on Oct. 22.