Jason Bay and the Mets ended an unproductive relationship after three seasons when they agreed Wednesday to terminate the outfielder’s contract with one guaranteed season remaining. The deal makes the 34-year-old former Red Sox outfielder a free agent and allows the team to spread out the remaining $21 million it owes him. After signing a $66 million, four-year deal before the 2010 season, the three-time All-Star hit .234 in three injury-plagued seasons with 26 homers and 124 RBIs, including a .165 average with eight homers and 20 RBIs this year . . . Free agent slugger Delmon Young pleaded guilty to aggravated harassment for shouting an anti-Semitic slur and tackling a man to the ground outside a New York City hotel last spring. He was ordered to complete 10 days of community service . . . Mark McGwire was hired as hitting coach for the Dodgers, the position in which he spent the past three seasons with the Cardinals. Former Sox infielder John Valentin was named assistant hitting coach . . . A judge sentenced former Yankees pitching prospect Brien Taylor to 38 months in prison after pleading guilty in August to distributing crack cocaine. Taylor, 40, was the No. 1 pick in the 1991 draft who never made the majors.