(CNN) -- Sen. Barack Obama's choice for running mate will be announced to supporters in a text message Saturday morning, senior Obama campaign officials told CNN on Friday night, and a senior party official said it won't be Sen. Hillary Clinton.
Sen. Barack Obama says he has decided on his running mate but is not yet ready to reveal the name.
Obama called some people on his short list for the vice presidential slot Thursday night to tell them he had not selected them as a running mate, a highly placed Democratic Party source said.
A senior Democratic official who had spoken with Clinton told CNN late Friday that the Obama campaign has communicated to her through private channels that she will not be Obama's vice presidential pick.
Also, sources close to Virginia Gov. Tim Kaine said he has been informed he was not selected. One source told CNN that Obama personally made the call to Kaine. Another source said Kaine has flown to Denver, Colorado, for the Democratic National Convention. See who's in the running
It is not known who else may have gotten calls.
However, late Friday two Democratic sources confirmed that Indiana Sen. Evan Bayh is also out of the running.
Rep. Chet Edwards said Friday that the campaign had vetted him but that he hasn't talked to Obama. Watch panelists weigh in on top VP contenders »
Edwards, 56, is a nine-term congressman representing the Central Texas district that includes President Bush's ranch near Crawford.
This month, House Speaker Nancy Pelosi touted Edwards as a dark horse contender for the No. 2 spot on the ticket.
The presumptive Democratic nominee was working Friday in Chicago, Illinois, on his address for the convention. He will launch a string of rallies with his running mate on Saturday in Springfield, Illinois.
Obama said Thursday that he had made his decision but declined to give further details.
"I won't comment on anything else until I introduce our running mate to the world," Obama said in Emporia, Virginia. "That's all you're going to get out of me." Watch Obama say he's made his choice »
Clinton re-entered the running mate conversation this week after a poll indicating that nearly half of her supporters have yet to embrace Obama.
The Wall Street Journal-NBC News poll out Wednesday night said 52 percent of Clinton supporters said they will vote for Obama. Twenty-one percent favor Republican Sen. John McCain, while 27 percent are undecided or say they will vote for "someone else.''
The poll has a margin of error of plus or minus 3.1 percentage points.
The former first lady was considered one of the top VP contenders shortly after she ended her White House run in June, but rumors of lingering tension between the former rivals and word that her name would be placed in nomination at the convention are partially to blame for political observers kicking her out of the top tier.
Other big names thought to be in the running included retired Gen. Wesley Clark, Sen. Chris Dodd of Connecticut, Sen. Chuck Hagel of Nebraska, former Sen. Sam Nunn of Georgia, Sen. Jack Reed of Rhode Island, New Mexico Gov. Bill Richardson and Kansas Gov. Kathleen Sebelius.
CNN's Jessica Yellin, Candy Crowley, John King and Ed Henry contributed to this report.