NASHVILLE (AP) — Sitting on the largest sum of campaign money among Republicans facing re-election to the Senate, few in Tennessee thought Bob Corker wouldn't run for a third term next year. His surprise announcement Tuesday that he will retire from Congress set off a frenzy of speculation about who will try to succeed him.

Attention quickly turned to Republican Gov. Bill Haslam, a close family friend of Corker's, who can't run for governor again next year because of term limits.

Haslam issued a statement praising Corker's service in the Senate, but a spokeswoman did not respond to questions about the governor's future plans. Tom Ingram, a campaign strategist for both Corker and Haslam, said he expects the governor to give a Senate bid serious consideration.

"While I don't think Haslam has any burning desire to run, I think he understands the importance of the office and of public service," Ingram said. "Bob's leaving big shoes to fill, and I think it's going to take the right person to fill them. I hope the right person will step up to it."

The governor laughed off questions last week about whether his newly announced policy cracking down on food stamp requirements might be designed to curry favor with the right wing of his party as he considers his political future.

"One hundred percent, no," he said. Pressed specifically about his Senate plans, Haslam said: "I love my job, thanks."

Former NFL and University of Tennessee quarterback Peyton Manning's political future has long been a source of speculation, especially after a highly publicized golf outing with President Donald Trump and Corker earlier this year. The quarterback also attended a Republican congressional retreat.

Manning's wife, Ashely, bought a share of the NBA's Memphis Grizzlies in 2012, and the quarterback is scheduled to be honored at halftime of the Tennessee-Georgia game in Knoxville on Saturday for his selection to the College Football Hall of Fame.

"It's not that Peyton shouldn't be taken seriously, but right now I think there's more people talking about Peyton than Peyton is talking about the Senate," Ingram said.

The only Republican who has declared for the Senate race so far is Andy Ogles, the former state director of Americans for Prosperity, the political arm of billionaire brothers Charles and David Koch's network. Others who might consider a bid include longtime U.S. Rep. Marsha Blackburn, who has often toyed with running for statewide office, and freshman Rep. David Kustoff, a former U.S. attorney in Memphis.

Former state Rep. Stephen Fincher, who retired from Congress last year, told The Tennessean he will decide by the end of the week whether he will run. He has $2.4 million remaining in his federal campaign account.

State Sen. Mark Green, who dropped out of the gubernatorial race after he withdrew from his nomination as Army secretary, is expected to announce his intentions in the next few days. Before Corker dropped out, former state Rep. Joe Carr said he was considering a bid.

Republican consultant Josh Thomas said a spirited primary — like the one Corker faced before his 2006 election — could help shape a stronger candidate.

"Energetic free-for-all primaries are good for the party and will produce a nominee who is ready to take on the Democrats in November," he said.

Nashville attorney James Mackler is the only Democrat in the race so far.