Concerned after the Miami Marlins and Pittsburgh Pirates cut major-league payroll, the baseball players’ association has taken the first step toward trying to force changes in the clubs’ behavior.

The union said it expressed concern to Major League Baseball that the teams are not spending revenue-sharing proceeds to improve play. The commissioner’s office responded by saying it is not worried about any violations.

Both teams are in the midst of rebuilds. The Marlins dealt major-league homer champion Giancarlo Stanton, Marcell Ozuna, Dee Gordon and Christian Yelich for prospects since new chief executive Derek Jeter’s ownership group bought the team in October, and the Pirates traded longtime franchise face Andrew McCutchen and ace pitcher Gerrit Cole.

Baseball’s collective bargaining agreement states “each club shall use its revenue sharing receipts ... in an effort to improve its performance on the field” and prohibits use of that money to service debt related to franchise acquisition and to debt not related to improving on-field performance.

“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,” union spokesman Greg Bouris said Friday. “We are waiting to have further dialogue, and that will dictate our next steps.”

Marlins to add nets

The Miami Marlins will install new netting at Marlins Park before the 2018 season to give fans along the baselines additional protection.

The netting is designed to blend with the playing surface and is 30 percent thinner than existing netting behind home plate, allowing better visibility, the Marlins said.

The new netting will extend the length of both dugouts at a height of 30 feet.

Jose Reyes joins Mets

Jose Reyes and the New York Mets finalized a $2 million, one-year contract, a deal that allows him to earn an additional $500,000 in bonuses based on plate appearances.

Now 34, Reyes was a four-time All-Star shortstop with the Mets from 2003-11 and left after winning the NL batting title to sign a $106 million, six-year contract with Miami. He was traded in November 2012 to Toronto and in July 2015 to Colorado, which released him in 2016 after Reyes served a 59-day domestic violence suspension.

Brewers sign Cain

Free-agent outfielder Lorenzo Cain and the Milwaukee Brewers finalized an $80 million, five-year contract.

A 31-year-old former Brewers farmhand, Cain spent the past seven seasons with the Kansas City Royals and was part of the core group that won the World Series in 2015.

He hit .300 with 15 homers, 49 RBI and 26 steals last season.

Orioles get infielder

The Baltimore Orioles acquired minor-league infielder Engelb Vielma from the San Francisco Giants for a player to be named or cash.

Vielma, 23, reached Triple-A for the first time last season. Since breaking into professional baseball as a member of the Twins’ organization in 2012, Vielma has played second base, shortstop and third base.