SAN DIEGO -- The Athletics' search for a new ballpark will be confined to Oakland, and Major League Baseball will put off any expansion talks until it solves its two outstanding stadium issues.

Baseball commissioner Rob Manfred said Tuesday the exact site is up to the team's owners, but he made clear the sport has no intention to allow a move outside the city.

"I am committed to Oakland as a major league site," he told the Baseball Writers' Association of America on Tuesday. "I think that if we were to leave Oakland, I think 10 years from now we would be more likely than not looking backwards saying we made a mistake."

Unhappy with the Oakland Coliseum, which opened in 1966, the A's considered building a ballpark in the southeast Bay Area city of Fremont and then scrapped that plan in 2009. They hoped to move to San Jose but were blocked by the San Francisco Giants, whose territory includes that Silicon Valley city.

"I think that Oakland is more likely than not to be a better market five years from now than it is today," Manfred said. "So I certainly have not given up on Oakland."

Manfred said the A's should go ahead with their stadium efforts, independent of the NFL's Oakland Raiders, who also want to leave the Coliseum for a new facility.

The Tampa Bay Rays also want a new ballpark, and were given permission by the St. Petersburg City Council to search for sites in the area outside the city.

Manfred said any move to add teams beyond the current 30 must wait because of the stadium searches.

"Both of those clubs need new major-league-quality facilities," he said, "and until that's resolved, I think expansion has got to be on the back burner for us."