Guillen joined a growing chorus of opposition to Arizona's new law that empowers police to determine a person's immigration status. The state is home to all four major team sports, hosts half the clubs in spring training and holds top events in NASCAR, golf and tennis.

The Major League Baseball players' union issued a statement condemning the law. A congressman whose district includes Yankee Stadium wrote a letter to baseball commissioner Bud Selig urging him to pull the All-Star game from Phoenix. The World Boxing Council took a step to limit fights in Arizona.

"It's a bad thing," said Baltimore shortstop Cesar Izturis, born in Venezuela. "Now they're going to go after everybody, not just the people behind the wall. Now they're going to come out on the street. What if you're walking on the street with your family and kids? They're going to go after you."

More than one-quarter of big leaguers on opening-day rosters were born outside the 50 states, most of them from Hispanic descent.

"These international players are very much a part of our national pastime," MLB union head Michael Weiner said. "Each of them must be ready to prove, at any time, his identity and the legality of his being in Arizona to any state or local official with suspicion of his immigration status."

Weiner said that if the law is not repealed or modified, the union would consider "additional steps."

A day earlier, WBC president Jose Sulaiman said its sanctioning body unanimously agreed it will not authorize Mexican boxers to fight in Arizona.

"Great figures of boxing have fought in Arizona, boxers such as Julio Cesar Chavez, Salvador Sanchez, Konstantin Tszyu, 'Coloradito' Lopez and many, many others," said Sulaiman, who is based in Mexico City. "The WBC will not allow that in boxing, athletes are exposed to suffer that degrading act, humiliating and inhumane, as racial discrimination is."

MLB, the NFL and the NBA declined comment on the law.

The BCS national championship game will be played next January in Glendale, Ariz., shortly after the city hosts the Fiesta Bowl.

"The recent Arizona immigration legislation is obviously a matter of great public concern," the Fiesta Bowl said in a statement Friday. "While this matter may ultimately be resolved in a court of law or in the court of public opinion, we are certain that it will not be resolved on the fields of college football."

Rep. Jose Serrano, D-N.Y., sent a letter Thursday night to Selig, asking him to take next year's All-Star game out of Arizona.

Calling the law "extremist" and "discriminatory," the congressman wrote: The All-Star game is now not just a display of baseball's best talent, but is also a display of the global reach of the game. It is at odds with the reality of the modern game to hold such a prestigious event in a state that would not welcome those same players if they did not play our national pastime."

St. Louis pitcher Kyle McClellan, the Cardinals' player representative, said he didn't know whether the summer showcase would get moved.