PITTSBURGH — Pedro Alvarez, the No. 2 pick in June amateur draft, was placed on Major League Baseball's restricted list today after his agent claimed the contract Alvarez agreed to with the Pittsburgh Pirates minutes before the Aug. 15 signing deadline is not valid.

Alvarez, the Vanderbilt third baseman, agreed to a minor league deal with a $6 million signing bonus, the amount the Pirates offered early in their negotiations with agent Scott Boras.

Boras would not comment on the deal after it was announced, and Alvarez has declined to sign the contract, the team said. Boras told the Pirates that Alvarez would not report unless the deal was renegotiated, the team said. He also claimed the agreement was reached after the midnight deadline for draft picks to sign on Aug. 15, according to the Pirates.

"Regrettably, we are not surprised that Mr. Boras would attempt to raise a meritless legal claim in an effort to compel us to renegotiate Pedro's contract to one more of his liking," Pirates president Frank Coonelly said in a statement, "We are, however, disappointed that Pedro would allow his agent to pursue this claim on his behalf. Pedro showed tremendous fortitude and independent thinking when he agreed to his contract on Aug. 15."

"The office of the commissioner has assured us that we have a valid contract with Pedro and that it will vigorously defend any claim to the contrary," Coonelly said.

"In fact, the contract between the Kansas City Royals and Eric Hosmer, another Boras client, was submitted to the office of the commissioner after our contract with Pedro was submitted," Coonelly said. "Mr. Boras is apparently satisfied with the $6 million bonus that he secured for Mr. Hosmer and has not challenged the validity of that contract. Mr. Boras has been informed that if he pursues a claim that our contract with Pedro was not timely, he puts Eric Hosmer's contract with Kansas City in jeopardy."

Boras declined comment, saying the Major League Baseball Players Association would speak for him. The union planned to file a grievance, sending the matter before arbitrator Shyam Das.

Hosmer, drafted immediately behind Alvarez, also received a $6 million signing bonus. No. 5 pick Buster Posey also got more from the Giants — $6.2 million — than Alvarez did from the Pirates.

The Pirates are determined, Coonelly said, to not let the contract impasse affect their relationship with Alvarez, a power-hitting third baseman who is considered a key to the Pirates' attempts to rebuild during a run of consecutive losing seasons that began in 1993.

"Despite our disappointment, we continue to believe that in Pedro Alvarez, the person and the baseball player, and remain excited to add Pedro to our system," Coonelly said. "We will sit down with Pedro as soon as Mr. Boras' claim is rejected to chart a new and more productive start to Pedro's career with the Pittsburgh Pirates."

The Pirates bypassed Boras clients previously because they were unwilling to meet his demands for signing bonuses over the slotting system designed when Coonelly a labor lawyer for MLB.

Once Coonelly accepted the Pirates job, he and general manager Neal Huntington said the team would not be scared off by Boras-represented clients and would draft players based on their ability, not their agent.