NASHVILLE - Republican U.S. Sen. Lamar Alexander's top aide as well as a long-time Alexander political adviser are pushing back against talk the senator won't run for a fourth term in 2020 amid speculation that retired NFL quarterback Peyton Manning might seek to succeed him.
Politico's Thursday "Playback" section, which rounds up news and political items, raised the issue about Alexander retiring as well as speculation about the political future of Manning, a former University of Tennessee football star quarterback and two-time NFL Super Bowl champion.
Tennessee's senior senator Lamar Alexander visited the Chattanooga Times Free Press for a conversation with the newspaper's editorial board. Senator Alexander discussed such topics as solar power and overtime pay issues. 
FILE - In this March 7, 2016, file photo, Denver Broncos quarterback Peyton Manning speaks during his retirement announcement at the teams headquarters in Englewood, Colo. (AP Photo/David Zalubowski, File)
"BUZZ: Several Republicans are wondering whether Peyton Manning will run for Sen. Lamar Alexander's (R-Tenn.) seat when he retires. GOP insiders say Alexander won't run for another term in 2020."
Alexander's office on Friday called it "unfounded rumor."
"Like everybody else in Tennessee, Senator Alexander is a big fan of Peyton Manning," said Alexander Chief of Staff David Cleary in a statement. "The senator has made no formal decision about 2020 but he's fundraising and taking the steps one would take to prepare for re-election."
Cleary noted Alexander had a 60 percent job approval rating in a December poll conducted by Vanderbilt University poll "and is busy as chairman of the Senate Health and Education Committee repairing the damage caused by Obamacare and implementing the law fixing No Child Left Behind."
Cleary said Alexander, 76, also remains "focused on maintaining a Republican majority in 2018 and helping Senator Corker with his campaign in Tennessee."
A former Chattanooga mayor, Corker, R-Tenn., is up for re-election in 2018.
Tom Ingram, Alexander's long-time political adviser, said "it's ridiculous to print rumors without any foundation" regarding Alexander. As far as I know, he is [running in 2020]. That's the message I got. And we're preparing full speed ahead."
For the 2018 cycle, Ingram said, "we're focused on Corker's reelection for the good of the Senate and then we'll move to his [Alexander's]. But every indication I've got and every expectation I have is he [Alexander] is full speed ahead. He's focusing on the job at hand right and he'll focus on that job when the time comes.
"I've been in this position with him a number of times and I think I can read his signals fairly clearly," added Ingram, who's been involved in Alexander's successful 1978 and 1982 campaigns for Tennessee governor as well as Alexander's successful 2002, 2008 and 2014 U.S. Senate races.
A veteran GOP political strategist agreed, saying Alexander has told him "he is running again."
Manning was invited this week to speak to congressional Republican leaders during the annual GOP retreat.
Fox News reported one congressional source told the network that Manning "told stories and talked about teamwork and leadership."
Other sources told Fox that Manning recounted a previously told story how as a freshman UT quarterback up against UCLA he sought to fire up teammates with an impassioned speech. The speech was cut off in mid-stride, Manning related, when offensive lineman Jason Lyman snapped "Just call the %&$ play!"
Both Alexander and Corker had welcomed Manning, a well-known contributor to Republicans, to the political gathering.
Fox News speculated Manning's Thursday "pep talk is likely to fuel speculation about whether Manning, who retired from the gridiron last year, will run for elected office."