The Major League Baseball players' union says it opposes the new Arizona immigration law.
The union says it's concerned the law could have a negative impact on hundreds of ballplayers and their families.
Union head Michael Weiner says in a statement released Friday that the law could force foreign-born ballplayers to prove their immigration status at any time. As of opening day, more than one-quarter of big league players were born outside the United States.
Weiner says the union hopes the law is repealed or modified. The All-Star game is scheduled to be played in Arizona in 2011.