Overnight last week, as Major League Baseball owners implemented a lockout, the league began acting as if its unionized players — those on 40-man rosters — no longer exist. 

The players have been scrubbed from the league’s website and content ecosystem. Their headshots were removed from rosters, their highlights hidden, their names wiped from promotional schedules. (April 30 is “Cardinals Third Baseman Bobblehead” day at Busch Stadium.) Team social media accounts quieted and ceased referencing players at all; the league’s Twitter account went nearly three days without activity this weekend. MLB Network and MLB.com employees were instructed to mostly avoid mentioning active 40-man players’ names on air or in articles for the duration of the lockout.

But exactly why MLB is taking this route isn’t clear. 

MLB is advised in labor relations by the law firm Proskauer Rose. Asked to explain the reason the league drastically altered its content vehicles, a commissioner’s office spokesperson said, “Every action we are taking is at the advice of legal counsel per the National Labor Relations Act.” The spokesperson declined, however, to identify what specifically in the NLRA or baseball’s collective bargaining agreement prompts or merits erasing current players.

When commissioner Rob Manfred was asked last week in a news conference whether it was a legal issue, he offered two words: “It is.” But legal experts who spoke to The Athletic found it difficult to confidently identify MLB and Proskauer’s potential legal theory.

“I can’t think of anything,” said Dave Leach, a professor at Brooklyn Law School and a former regional director for the National Labor Relations Board. “I’ve never seen a case which had similar facts. And I was there for 45 years, so I saw a good number of cases at the board.”

Bruce Meyer, the lead negotiator for the players’ union, said MLB made the decision on its own, “and you’ll have to ask them for their reasons.”

“It’s a little bit of a mystery why they think this is somehow required legally,” said Jason Wojciechowski, a lawyer at Bush Gottlieb and former editor at Baseball Prospectus. “I don’t know what aspect of the law they think they’d be in violation of. As a union lawyer, my suspicion is that’s cover. But on the other hand, cover for what?”

Nathaniel Grow, a professor of business law and ethics at Indiana University who writes for FanGraphs, thought it was fair to wonder whether MLB could be applying a pressure tactic. But if so, it might not be a particularly effective approach.

“How much pressure does it really apply?” Grow said. “Is it more of just an aggravating tactic? Are the players going to cave on a second-year arbitration (demand) because their pictures are down from the website? Probably not.”

Said an MLB spokesperson: “These actions are not intended to punish players in any manner whatsoever.”