Major League Baseball has sent a warning to clubs about encouraging players subject to the MLB draft to withdraw from high school baseball to become eligible to sign as international players. An MLB spokesman declined comment.

The key section of the memo sent to teams Monday and obtained by ESPN reads: “It has come to our attention that Clubs have been encouraging amateur players in the United States to withdraw from, or otherwise refrain from playing, high school baseball in the United States and/or Canada, in order to try to establish residency in a foreign country, in an effort to make themselves eligible to sign under the International Amateur Talent System instead of the Rule 4 Draft.”

In the MLB draft, picks largely cannot be traded, so teams’ access to elite players is largely determined by their draft order. In the international system, teams have similar-sized bonus pools, and any player is able to be negotiated with. All but the best handful of players are acquirable by every team in the international market.

In the memo, the league clarified the rules around eligibility and what rules teams were breaking by encouraging players to change their eligibility. The memo says that encouraging players to make this change “shall be subject to significant penalties, including, but not limited to, the denial of player selection rights under the [MLB draft] or loss of benefits under the International Amateur Talent System.”

A recent example of a legal version of this maneuver was made by shortstop Lucius Fox in 2015. He was a native of the Bahamas who had moved to Florida to play high school baseball and was regarded as a fringe first-round prospect after his junior year of high school. Fox moved back to the Bahamas and was declared a free agent by the league in April 2015, eventually signing for $6 million with the San Francisco Giants in July 2015.

The international bonus pools weren’t hard-capped then like they are now, so that sort of bonus is unlikely, but this illustrates the potential benefit of this kind of move. Fox would’ve received roughly half that bonus if he had stayed in the draft process, but he was evaluated differently as an 18-year-old in the international market, where the biggest bonuses are largely given to 16-year-old prospects. Fox, now 26 years old, is a free agent. He has played in 10 big league games, all in 2022 for the Washington Nationals.