Yang signed a one-year deal with the Tigers as a free agent after the 2016 season, and he isn't eligible for international free agency until 2020. He can only test international waters if the Tigers agree to post him, as they did after the 2014 season. An unidentified MLB club put a bid on Yang but the Tigers rejected the offer.

MLB also had a status check on Son in October.

Under an agreement between the MLB and the KBO, a major league team interested in a South Korean player, professional or amateur, must send the status check through the league offices. Once MLB requests a status check, the KBO must respond within four business days. MLB must keep under wraps the identity of big league clubs inquiring about the Korean players' status.

Yang, 29, may be the biggest prize of the three, but he has publicly said he'd like to return with the Tigers next season. Yang was voted the regular season MVP last week after going 20-6 with a 3.44 ERA, a solid number in a league where no pitcher had an ERA below 3.00 and 33 qualified batters hit .300 or better.

Yang was also the Korean Series MVP after helping the Tigers to their first title since 2009. The lefty threw a complete game shutout victory and picked up a save in the championship clinching Game 5 against the Doosan Bears.

Son, also 29, is coming off a strong offensive season. He slashed .335/.420/.514 with a career-high 20 home runs and 80 RBIs, while stealing 25 bases for his first 20-20 season. Son topped the KBO with 193 hits, the third time he's led the league in that category.

Son was eligible for posting in 2015 but drew no bid from MLB clubs at the time.

Jung, 31, is a late bloomer whose power numbers dipped in 2017. He batted a career-best .321 this year, but only had 15 home runs and 45 RBIs, a far cry from 27 homers and 100 RBIs a year ago. (Yonhap)