Woods, who turned 41 last week, has 14 major titles and in 2017 will resume his chase of Nicklaus' record of 18 after missing roughly 14 months because of two back procedures.
"I've always thought that he's got at least another 10 years of good competitive golf in front of him, if he's healthy and as talented as he is," Nicklaus said. "I don't think anything is safe.
" ... I would think he'll do all right. He'll play well. I don't think the injuries are going to be a big issue for him. The biggest issue is going to be between his ears, how does he mentally get back in the game?"
Nicklaus, who won the 1986 Masters at age 46, also noticed that Woods spent much of his time off immersing himself more deeply in his golf course design business and spending time with his children. He believes that will help Tiger in the next phase of his career.
It's a page right out of the Golden Bear's book.
"I always did what I had to do," said Nicklaus, a prolific course designer. "If my day was filled up with golf, it would be a boring day for me. I needed more stimulation. I think business and my family and some things I did on the outside created my away time, so that when I came back to play golf, then I really focused on it.
"If golf was all I had, I would have gotten lazy with it. I tried to be very efficient."
McIlroy, 27, has claimed four major titles but has run into a bit of a dry spell since winning the 2014 PGA Championship at Valhalla.
The native of Northern Ireland will make his third bid to complete the Career Grand Slam at the Masters in April, and Nicklaus believes Rory has to take his game to another level to be truly great.
"He has won and played on his talent to this point," Nicklaus said. "If he wishes to dominate and go forward, then he's got to improve. He has to work hard, he's got to focus on what he is trying to do and it is up to him. Certainly he has all the tools to be able to do it -- it is just whether he has the desire and the willingness to give up some other things.
"Whether he wants to be the greatest player to have played the game, that's his determination and it's his decision whether he wants to make that effort to try to do that."
As for the Masters: "He certainly has the type of game that would do well at Augusta and he has done well before -- he just hasn't finished it," Nicklaus said. "He'll win it. He's a good player."
The question is, can McIlroy or Woods surpass Nicklaus as the G.O.A.T. in their sport?
Lefty, a native of San Diego, has won his hometown event three times. In fact, of his 42 PGA Tour victories, 16 have come in California and Arizona, where he also is a fan favorite because he played at Arizona State.
The 46-year-old Mickelson underwent hernia surgery on Oct. 19, a few days after he tied for eighth in the Safeway Open at Silverado in Napa, Calif. His management team announced that he underwent a follow-up procedure recently.
There was no word on whether or not Lefty could play the week before the Farmers in the CareerBuilder Challenge at PGA West in La Quinta, where he often starts his season.
Mickelson has won the California Desert event twice and has said he will be on hand even if he does not play, having recently taken over for former President Bill Clinton as ambassador of the event.
Jim (Bones) Mackay, Lefty's longtime caddie, underwent knee replacement surgery in October and has said he believes he will be ready to go whenever Mickelson starts his season.
--Famed Cypress Point Club in Pebble Beach will host the 50th Walker Cup matches in 2025, the United States Golf Association announced.
The Walker Cup, which dates to 1922, has been played only twice in California, including when Corey Pavin of Oxnard and UCLA helped lead the United States to victory over Great Britain & Ireland in 1981.
The classic course at Cypress Point, designed by legendary Alister MacKenzie, features one of the most famous holes in the world -- the par-3 16th.
The USGA also announced that the 2021 Walker Cup will be played at Seminole Golf Club, designed by Donald Ross, in Juno Beach, Fla. The site of the 2023 matches in the United Kingdom or Ireland has yet to be announced.
"The selections of Seminole Golf Club and Cypress Point Club as Walker Cup venues are emblematic of what George Herbert Walker intended when he helped create the first match in 1922," said Stuart Francis, USGA Championship Committee chairman.
"To have two of the United States' greatest courses as host sites will not only produce memorable competitions but reinforces the stature of amateur golf in this country."
The 2017 matches will be played at Los Angeles Country Club, which also will host the 2023 U.S. Open, and the 2019 Walker Cup will be hosted by Royal Liverpool Golf Club in Hoylake, England.
The United States holds a 35-9-1 lead in the Walker Cup matches, having won four of five before Great Britain & Ireland won 16 1/2-9 1/2 last year at Royal Lytham & St. Annes Golf Club in Lancashire, England.
--Beth Allen of San Diego became the first golfer from the United States to capture the Ladies European Tour Order of Merit title in the 38-year history of the organization on the strength of two victories in 2016.
The 35-year-old Allen also earned the LET's Player of the Year award and received both trophies at the tour's annual awards dinner before the season-ending Omega Dubai Ladies Masters
"I love this tour and I'm so grateful to be part of it," said Allen, who played college golf at Cal State Northridge. "Winning this means so much to me, especially because it's voted for by the members.
"In 2008, I joined the LET as a struggling tour pro with the desire to travel and I thought, 'What a great idea! I can play golf and I write off all of my travel expenses while seeing the world.' What I didn't expect was for the tour to inspire me to become a better player. Now, many countries, a few wins and lots of laughs later, I'm standing up here as the first American ever to win the Order of Merit and I'm so proud of that achievement."
Allen, who has secured her LPGA Tour card for next season, captured the Lacoste Ladies Open de France and the inaugural Fatima Bint Mubarak Ladies Open in Abu Dhabi in consecutive events and posted six other top-10 finishes, including second in the Andalucia Costa del Sol Open de Espana.
Allen, whose only other LET victory came in the 2015 ISPS Handa Ladies European Masters at Buckinghamshire Golf Club near London, owns a home in Edinburgh, Scotland, and plans to play both tours in 2017.
--A letter filed by the Department of Justice claims an FBI agent leaked confidential information regarding the insider trading probe of PGA star Phil Mickelson and gambler Billy Walters to the media during the investigation.
U.S. attorney Preet Bharara said the agent admitted giving information to reporters from the New York Times and Wall Street Journal for seven articles published between May 30, 2014, and June 23, 2014.
Those articles, which the letter said contained "sensitive and confidential details, including trades being examined, records being analyzed, the name of an individual approached by the FBI and the supposed targets of the investigation," led to Walters and Thomas C. Davis, a former executive for Dean Foods, being indicted.
Walters' trial is scheduled to start July 29 in New York.
"The agent further admitted that, prior to his Dec. 6 interview, he had hidden those communications with the press from both the U.S. Attorney's Office and others within the FBI," Bharara said.
The letter claims the agent was reported to the FBI's Office of Professional responsibility, and the issue was brought to the Office of Inspector General for the Department of Justice.
Mickelson was not charged but agreed to repay more than $1 million of "ill-gotten gains" from stock trades he and Walters made on Dean Foods in 2011.
--Tiger Woods played a round of golf with President-elect Donald Trump at Trump International Golf Club in West Palm Beach, Fla., during the Christmas holidays, according to media reports.
Woods, who returned to competitive golf early this month at the Hero World Challenge, and Trump played in a foursome with two club members, according to Golf Digest.
In February 2013, Woods joined President Obama for a round at the Floridian Yacht and Golf Club in Palm City, Fla.
Trump, who according to Golf Digest carries a 2.8 handicap, presented the trophy to Woods after he won the 2013 WGC-Cadillac Championship at Trump National Doral in Miami.
Woods returned from a 15-month layoff after two back procedures and tied for 15th in the 18-player field at the Hero World Challenge at Albany Resort in the Bahamas.
Tiger's next scheduled tournament is the Genesis Open in February at Riviera Country Club in Pacific Palisades, near Los Angeles. The event benefits the Tiger Woods Foundation and he is the tournament host.