AP

So when will Rick Santorum and Mitt Romney meet in person, a step closer to the former rival's backing the presumptive nominee? Not for at least two to three weeks, Santorum's longtime adviser and strategist John Brabender said.

Brabender says he has been talking to Romney campaign manager Matt Rhoades and they have been looking at dates in the next two to three weeks for a possible meeting.

"They are going to just sit down and talk about a few things on the agenda,"  Brabender said. "One of the things that will be discussed is a potential endorsement."

But it won't just be an endorsement Romney and Santorum will discuss.

"The senator takes his endorsement very seriously and he will want to get some assurance that some of the issues that are very important to him will be important in a Romney administration. That's why I think they need to have a conversation," Brabender said before adding that the former Pennsylvania wants to stay active in the election.

Santorum stressed Monday on a phone call with supporters that despite his not endorsing yet, there is "no question Barack Obama has to be defeated," saying he will be helping Republican candidates up and down the ballot and describing himself as being "all in," as he did during his NRA speech last week.

Brabender repeated that refrain, saying Santorum is focused on making sure Obama is a one-term president and that he is "interested in Romney's thoughts on how Rick might be helpful in  making sure we have a Republican president."