The Kiwoom Heroes said Wednesday they have signed veteran infielder Lee Won-seok to the first multiyear contract in franchise history.

Lee, 36, agreed to a new two-year contract, plus a vesting option for a third year -- meaning, if Lee reaches a certain performance incentive threshold, the third season becomes guaranteed. Lee was scheduled to become a free agent following the 2024 season, but the Heroes gave him additional security with Wednesday's deal.

In July 2021, the Korea Baseball Organization started allowing clubs to sign players to multiyear contracts before hitting free agency. The SSG Landers, the NC Dinos and the Lotte Giants have since taken advantage of the rule change to lock down key players before risking losing them for nothing.

Prior to that, KBO players had only been allowed to sign one-year deals before hitting free agency.

Players coming out of high school must spend eight full seasons before hitting free agency. Those who graduate from four-year colleges become eligible for free agency after seven full seasons.

Players who have already been free agents once can hit the open market again after four seasons.

Lee is set to make 400 million won ($305,560) in 2024 and 300 million won on in each of the following two seasons. The deal is pending the KBO's final approval on Feb. 1, 2024.

The Heroes traded for Lee on April 27 in exchange for reliever Kim Tae-hoon. Lee was batting .355 at the time of the transaction. In 49 games as a Hero prior to Wednesday, however, Lee was only batting .237 with a home run and 11 RBIs.

Overall, Lee is batting .268 with a couple of homers and 21 RBIs in 68 games. The versatile fielder has played at first base and third base, while also spending time as designated hitter.

Lee's so-so numbers notwithstanding, the Heroes said they still valued Lee's leadership skills for the youthful squad.

"He has made a quick transition to the new team after the trade and has been setting a good example for younger players with his work ethic," Heroes general manager Ko Hyung-wook said. "We hope he will continue to inject positive energy on and off the field."

Lee thanked the club for the multiyear deal, saying it provided him with an extra dose of motivation.

"I no longer have to worry about job security after the season and can just focus on baseball," Lee said. "I will do my best to be a good teammate here."