The two announcements heightened speculation Guillen might be bound for the Marlins, where he was McKeon's third-base coach with the 2003 World Series champions.
Marlins officials didn't return phone calls seeking comment, and McKeon was coy about the possible hiring of Guillen.
"I like Ozzie," McKeon said. "I think he's a very, very intelligent manager. He was a smart player. He's a good man. I like him."
With a smile, McKeon added, "I'm going to have to like him, right?"
Guillen was released from his contract with the White Sox on Monday to pursue other opportunities, and there has been speculation for more than a year that his next move would be to Miami.
He worked for Marlins owner Jeffrey Loria as their third base coach in 2002-03. After they won the World Series, Guillen became the White Sox manager that November.
With the Marlins moving into a new ballpark next year, Loria has said he wants to hire an experienced manager.
McKeon's retirement announcement had been anticipated, and it ended his three-month career comeback at age 80. He's the second-oldest manager in major league history, and he joked he hopes to come back in a few years to surpass Connie Mack, who managed the Philadelphia Athletics until age 87.
"I'll still be on call," he said with a chuckle. "Hopefully in 2017 or '18 I'll be back. That would be the big motivation -- to beat Connie."
McKeon also came out of retirement in 2003 and led the Marlins to an improbable World Series title five months later. He retired again at age 74 following the 2005 season, but returned in June as interim manager after Edwin Rodriguez resigned.
"If I had to take a poll of my family, they wouldn't have wanted me to come back this year," McKeon said. "But out of my loyalty to the organization, I just had to."
He took over when the Marlins were 32-40 and led them to .500 in early August before a wave of injuries hit and they sank to last place in the NL East.
"I'm disappointed I couldn't work the magic we had in '03 here, but I think you guys understand the circumstances," McKeon said.
The next manager will be the fourth since early 2010 for the Marlins.
McKeon's old-school tactics caused some grumbling this year by players two generations younger, but he was always quick to note the same approach worked in 2003. The Marlins' astounding success that season made McKeon a folk hero with fans, and he still gets big ovations when he walks to the mound to change pitchers.
McKeon began his professional baseball career as a minor league catcher in 1949 and managed 2,269 games in the minors. He took his first big league managerial job with Kansas City in 1973 and has also managed Oakland, San Diego and Cincinnati, nearly leading the Reds to a wild-card berth in 1999, when he won NL Manager of the Year.
He's seventh in victories among active managers. Through Sunday his career record was 1,050-988, with a franchise-record 280 wins for Florida.
McKeon wants to remain with the franchise as a consultant. His more immediate plan is to fly home to his wife, dog and yard in North Carolina.
"I'll probably leave Friday," he said, "and on Saturday I'll get back on the mower."