The baseball players' union is going to bat for workers at New Era's Derby plant.

It's urging the company to keep its plant in Derby open.

New Era has been Major League Baseball's cap supplier since 1993.

The company announced it planned to shut down the site in March and reached an agreement with the union earlier this month.

The MLB players association says the decision will "cause economic harm" to the workers and Derby.

More than 200 workers will be out of a job.