The home run ball that saw Japanese superstar Shohei Ohtani become the first player in Major League Baseball history to hit 50 homers and steal 50 bases in one season is for sale, auction house Goldin said Wednesday.

Bidding will start Friday at an opening price of US$500,000, although buyers have a chance to purchase the ball outright for US$4.5 million between September 27 and October 9, according to the listing on the Goldin website.

If bidding reaches US$3 million before October 9, Goldin will remove the option to purchase it privately, and interested parties must bid for the baseball.

The record price for a baseball is US$3.05 million paid for Mark McGwire's 70th home run ball of 1998.

"This offered baseball is truly a one-of-a-kind specimen, a crowning piece for any game-used memorabilia collection," the listing says, adding that the ball "exhibits excellent game use, with black scuffing and surface abrasions present throughout the white leather surface."

Ohtani's 50th home run of the season came during a spectacular offensive outing for the Los Angeles Dodgers against the Marlins in Miami on September 19.

He had six hits in six at bats, including two doubles for a total of five extra-base hits.

He drove in 10 runs, scored four and stole two bases to help the Dodgers clinch a post-season berth that will mark Ohtani's first trip to the MLB playoffs.

"This was one of the easiest consignments ever," Ken Goldin, founder and chief executive of the auction house, told ESPN.

"Ohtani hits 50 on Thursday, and on Friday we heard from the guy," he added. "He contacted Goldin on his own through social media, flew a security guard down to Miami on Monday with a representative from Goldin, met him, flew back Monday". (AFP)