Samson said the 80-year-old McKeon works harder than many people half his age and seems even sharper mentally than in 2003, when he led the Marlins to an improbable World Series championship.
In response to the comments, a grinning McKeon intentionally messed up Samson's name.
"Thanks, George," McKeon said.
The new, old skipper drew some laughs at his re-introductory news conference Monday, but the hiring was no joke. Nearly six years after McKeon retired as the Marlins' manager, he returned to his former job on an interim basis and will lead the team for the rest of the season.
He becomes the second-oldest manager in major league history. Connie Mack managed the Philadelphia Athletics in a suit, tie and straw hat until 1950, when he was 87.
McKeon will wear a uniform with No. 25.
"I've managed since I was 14 years old," he jokingly said. "I'll probably manage until I'm 95."
The cigar-chomping McKeon succeeds manager Edwin Rodriguez, who resigned before Sunday's loss at Tampa Bay. Last-place Florida took a 10-game losing streak into Monday night's matchup at home against the Los Angeles Angels.
McKeon's first lineup card caused a stir, because it didn't include 2009 NL batting champion Hanley Ramirez, who has been in a slump all season.
"I didn't think he was running very good (Sunday)," said McKeon, who watched the game on TV from his home in North Carolina. Ramirez has been battling a sore back but also has a reputation for a lack of hustle, and McKeon declined to say which he thought was the issue.
Ramirez had no complaint about being held out of the lineup and said he welcomed McKeon's old-school approach.