Tomoyuki Sugano did not come to an agreement on a contract with a Major League club before his posting window expired and will return to Nippon Professional Baseball for 2021.
The bidding for the right-hander started Dec. 8 and ran through 5 p.m. ET Thursday.
Sugano will be eligible to come to the Majors as a free agent before the 2022 season.
The 31-year-old was 14-2 with a 1.97 ERA and three shutouts in 20 games last season.