The baseball players union has filed a grievance against the Tampa Bay Rays, Oakland Athletics, Pittsburgh Pirates and Miami Marlins for not spending more money.

The union claims that these teams have not correctly complied with rules on how to spend their revenue sharing money, according to Marc Topkin of the Tampa Bay Times.

Teams are required to spend their revenue sharing money to improve the on-field product, as part of the guidelines in the collective bargaining agreement. The Rays receive some of the most revenue sharing money, reportedly in the $45 million range annually.

“We have received the grievance and believe it has no merit,” MLB told the Tampa Bay Times.

The grievance is in response to the 2017 season and this winter.

“We have raised our concerns regarding both Miami and Pittsburgh with the Commissioner, as is the protocol under the collective bargaining agreement and its Revenue Sharing provisions,” the union said in a statement, as reported by USA Today. “We are waiting to have further dialogue and that will dictate our next steps.”

MLB responded by saying, “We do not have concerns about the Pirates’ and Marlins’ compliance with the Basic Agreement provisions regarding the use of revenue sharing proceeds. The Pirates have steadily increased their payroll over the years while at the same time decreasing their revenue sharing.

“The Marlins’ ownership purchased a team that incurred substantial financial losses the prior two seasons, and even with revenue sharing and significant expense reduction, the team is projected to lose money in 2018. The Union has not informed us that it intends to file a grievance against either team.”

It’s currently uncertain as what the penalties will be if the teams are found guilty.