Giancarlo Stanton says he spent many sleepless nights pondering his long-term commitment to the Miami Marlins who signed the slugger to the largest contract in North American sports history on Wednesday.
The jaw-dropping 13-year, $US325 million ($A352 million) contract runs through the 2027 season and includes a club option for 2028.
"I stayed up multiple nights thinking about this," said the 25-year-old Stanton.
"No matter what people think it was not the money fuelling this.
"This was the toughest decision of my life. This is 13 years. I didn't even go to school for 13 years."
The 25-year-old Stanton is one of the most feared power hitters in American baseball.
He finished runner-up to pitcher Clayton Kershaw for National League MVP honours after a superb 2014 Major League Baseball season that included an NL-best 37 homers and a career-high 105 runs batted in.
"We know we have some of the best young talent in baseball. Now we have the cornerstone," said Marlins' president Michael Hill.
The contract will also include an opt-out clause after six seasons which Stanton says he asked for.
"That is one of main components. That was for my protection," Stanton said.
The contract would top the $US292 million, 10-year deal Miguel Cabrera signed with the Detroit Tigers in March.
Stanton said the contract is about getting the Marlins on the right track towards winning a championship.
"If I am not performing and we are winning I am cool with that," Stanton said.
"Everyone wants to talk about the record breaking deal. That is for (reporters) to talk about. I want to talk about breaking records on the field."
In 634 career games, Stanton has 154 homers and 399 RBI with a career .271 batting average.
