Barack Obama said Thursday he doesn't anticipate any problems with Hillary Clinton supporters at the Democratic National Convention after a video surfaced of Clinton telling backers that her delegates should have a role in Denver.

Clinton last week seemed to leave open the option for a symbolic roll-call vote at the convention later this month.

But she later assured her supporters in an online chat that "Senator Obama and I are working together to make sure it's a big success."

Obama told reporters on his campaign plane that he talked with Clinton and her husband, and that they are enthusiastic about having a smooth convention.

"She is very enthusiastic about the need for a unified party. I think we're gonna have a terrific convention as is true in all conventions," he said. "We're still working out the mechanics of the four days and our staffs are in communication with Senator Clinton's staffs but I don't anticipate any problems."

Clinton and Obama have made at least four appearances together and she has solicited financial support for Obama from her fundraisers since she endorsed him on June 7, pledging to "join forces" to "make history " and put Obama in the White House.

Clinton says her defeating Obama at a contested Democratic National Convention "is not going to happen" but she is looking for a way for her delegates to vent before getting behind the future nominee ahead of the November election.

Clinton said earlier that her delegates want to have a role and feel that their "legitimacy is validated," before the group moves forward to back Obama.

"I happen to believe that we will come out stronger if people feel that their voices were heard and their views respected. I think that is a very big part of how we actually come out unified," Clinton, D-N.Y., said to applause.

"Because I know from just what I'm hearing, that there's incredible pent-up desire. And I think that people want to feel like, 'OK, it's a catharsis, we're here, we did it, and then everybody get behind Senator Obama.' That is what most people believe is the best way to go," she said.

"Doesn't work that way," shouted one supporter. The video clip of her remarks was posted on YouTube accompanied by the one-word remark, PUMA, an acronym for a group of Clinton supporters who have not committed to Obama. PUMA stands for "Party Unity My A--."

Click here to see the YouTube video of Clinton.

Asked if he thought it would be cathartic for Clinton's name to be put in for nomination, Obama said: "I don’t think we’re looking for catharsis. I think what we’re looking for is energy and excitement about the prospects of changing this country."

In the original video, Clinton said that she is fully behind Obama and actually has offered more help to him than other candidates have done for other nominees in previous years.

"I think it's fair to say if you look at recent history, I have moved more quickly and done more on behalf of my opponent than comparable candidates have. And most of them didn't endorse until the convention," she said, naming Massachusetts Sen. Ted Kennedy, former California Gov. Jerry Brown and former Colorado Sen. Gary Hart, all past presidential candidates who lost the party nomination.

Obama spokesman Bill Burton told FOX News that nothing has been decided in terms of the role of Clinton's delegates. He said Democrats remain united, despite the hard-fought battle between Clinton and Obama, and about 20 former Clinton staffers are helping the Obama campaign.

Clinton and Obama also issued a joint statement Wednesday night saying that they are cooperating to include everyone in the convention and election process.

"We are working together to make sure the fall campaign and the convention are a success. At the Democratic Convention, we will ensure that the voices of everyone who participated in this historic process are respected and our party will be fully unified heading into the November election," they said.

The Democratic convention is being held in Denver on Aug. 25-28, with the first three nights' activities taking place at the 21,000-seat Pepsi Center.

Obama is expected to accept the nomination at Invesco Field at Mile High, a 75,000-seat stadium where the Denver Broncos play. Convention planners said the venue would demonstrate the massive support Obama commands.

"You don't have to be a delegate or party insider to witness this historic moment firsthand," Democratic National Convention Committee CEO Leah Daughtry said, announcing the plans for credentials.

Ticket selection was designed "to showcase the gains the party has made in the West," she said. Nearly two-thirds of the tickets will go to residents of the West and Southwest, including Colorado, where Democrats have made inroads in recent elections.

But several of Clinton's supporters are insistent that the former first lady get a vote on the convention floor. One self-identified delegate at the California fundraiser said a petition had been formed to put Clinton's name on the ballot.

Clinton did not oppose that idea, but said it won't change the outcome.

"I have made it very clear that I am supporting Senator Obama and we're working cooperatively on a lot of different matters, but I think that delegates can decide to do this on their own. They don't need permission. They can decide under the rules of the DNC, and so I think it would be better if we had a plan that actually we put in place and everybody knew what it was and then we executed it because I just think that would go more smoothly," she said.

Former Clinton campaign manager and FOX News contributor Howard Wolfson also obliquely acknowledged Thursday that relations between Clinton's and Obama's delegates aren't all roses and sunshine.

"You know the these two people ran against each other for 18 months there were some moments of ... friction as you might imagine," he said, stressing that Clinton is doing her part to contribute to Obama's election.

"If you have some people that are concerned that they are not getting the respect that they are looking for, that the party not quite yet unified, what is the way to bring those people back into the party to make sure that they are enthusiastically supporting Senator Obama by the time the November election comes around? And one possible way of doing that is to have roll call that has Senator Clinton's name placed in nomination, that is one option. There are other options and I think that the important thing is that this is going to get decided between Senator Clinton and Senator Obama in a way that I think both can agree unifies the party and bring people together," he said.

Democratic strategist and FOX News contributor Bob Beckel added that a vote for Clinton would help relieve some of the tension between the Obama and Clinton delegates.

"They can't stop them if they want to do it. They cast their vote for Hillary Clinton and before the final roll call is finished they are going to go back through and make it unanimous by state. That's one way I think to let a little bit of the pressure out of this pressure cooker, but it's there. I mean it's bound to be. You can't have a convention with 1,800 delegates out of 4,400 be for somebody else and not expect there is still going to be some latent animosity," Beckel said.

Clinton is expected to deliver a prime-time address to delegates on Aug. 26, the second night of the gathering. Typically the vice presidential nominee delivers the address on the third night of the convention.

FOX News' Bonney Kapp, Steve Brown and Corbett Riner and The Associated Press contributed to this report.