After months of speculation over what his early gamble on Donald Trump might earn him, Gov. Christie didn't win a spot on the presumptive GOP nominee's ticket.

On Friday, Trump - on Twitter - named Indiana Gov. Mike Pence as his running mate. Just the night before, on Fox News, Trump had listed Christie among his three finalists.

Political observers say the vice president announcement doesn't diminish the role Christie may play in Trump's campaign - or the prospect of a Trump administration job for the governor, who was among the first establishment Republicans to back the political outsider after his own presidential bid collapsed in February.

Christie has been serving as chairman of Trump's White House transition team.

"I think he'll play a major role in the campaign, and it may not be visible," said Tom Rath, a Republican strategist in New Hampshire who advised the campaigns of Ohio Gov. John Kasich and 2012 GOP nominee Mitt Romney, among others.

Given Christie's background in the "nitty-gritty" of government, "he looks more and more to me like a chief of staff of a White House than a vice president," Rath said. A former U.S. attorney for New Jersey, Christie also has been seen as a possible pick for attorney general.

Christie said in an interview with MSNBC Thursday that "I haven't really given any thought" about other roles in a Trump administration. "What matters most to me is helping him get elected president," Christie said.

But he acknowledged that not being chosen for the running mate role would be a disappointment.

"If you're a competitive person like I am . . . you don't like coming in second, ever," he said.

Christie was also vetted for vice president by Romney in 2012 - a campaign in which Christie turned down entreaties to run for president himself.

While Christie would have given Trump governing experience and the ability to go on the attack on the campaign trail, he presented drawbacks as a running mate, Republican strategists said.

The governor didn't win much support in his own presidential campaign and has faced skepticism from conservatives. Christie wouldn't have broadened the geographic reach of Trump, a New Yorker, and he isn't popular at home: His approval ratings in New Jersey have dipped as low as 26 percent in recent polls.

And while his big personality would have doubled down on the businessman's blunt-talking brand, for a ticket that "might need to show its softer side, he doesn't do that," said Bruce Haynes, a GOP strategist and president of Washington-based Purple Strategies.

The George Washington Bridge lane-closure scandal that scarred Christie's second term also remains a story line. The vice presidential announcement came the day after Christie confidante David Samson, former chairman of the Port Authority of New York and New Jersey, pleaded guilty to federal corruption. And two of his former allies are scheduled for federal trial in September, when the presidential campaign will be heating up.

"If you bring ethical baggage onto your own ticket, you risk losing the punch" of a contrast with Clinton, Haynes said. The former secretary of state has been dogged by questions about her handling of classified information on a private email server.

Christie has said he and Trump have known each other for 14 years. During his presidential campaign, he referred to "Donald" as his friend.

For Trump's relatives, Christie is notable for a different role. As U.S. attorney, Christie prosecuted real estate developer and Democratic fund-raiser Charles Kushner for tax evasion, making illegal campaign donations, and witness tampering.

Kushner, who was sentenced to two years in jail in 2005, is the father of Jared Kushner, who married Trump's daughter Ivanka in 2009.

Despite not being chosen as Trump's running mate, Christie's "political future is going to be very closely aligned with Donald Trump's brand from now on," said Kevin Madden, who advised Romney's campaigns. "All of the good and all of the bad that come with Donald Trump's political profile is going to be owned by Chris Christie."

In endorsing Trump, Christie was accused of political opportunism, including by critics within his party.

The narrative may have complicated his chances of being vice president. "What you don't want is three months of reading stories of Christie going through the drive-through at McDonald's for him," Rath said, referring to an anecdote in the New Yorker that Christie had retrieved McDonald's for Trump. (Christie's team denied the mention, which the magazine credited to an anonymous source.)

"When you establish a narrative like that, it's hard to break it," Rath said.