ST. PETERSBURG — Mayor Bill Foster has reached the reluctant conclusion that keeping the Tampa Bay Rays in the region means he has to let them cross the bay to explore a new stadium.

Three years ago, Foster adamantly refused a team request to look at stadium sites in Hillsborough County — citing a contract that binds the Rays to Tropicana Field through 2027.

But tepid attendance over the last few years has changed his thinking, Foster said in a remarkably candid interview Monday with the Tampa Bay Times editorial board.

"If your goal is keeping the Tampa Bay Rays in Tampa Bay until 2050, you have to let them look in Tampa," Foster said.

Attendance might not improve markedly at a Hillsborough site, Foster said. "I think there is a big question mark as to whether or not Tampa Bay is a major league region.''

But letting the Rays explore all options now will enhance chances that the team stays for the long haul, he said.

Michael Kalt, the Rays senior vice president of development and business affairs, declined to comment.

Foster and the Rays have quietly negotiated for months on a legal framework that would let the team explore possible Hillsborough sites. On Monday, Foster publicly explained his thinking for the first time.

The team is averaging 18,476 fans a game — second worst in baseball — despite big crowds last weekend for the World Series champion San Francisco Giants.

The recession is winding down, and "you've got the hottest team in baseball, you're in a fight in the AL East, and you're not breaking 20,000. That sends a message to a lot of people,'' Foster said.

"It's a flag to the entire community. Are we a major league community? Are we a major league region? I think people need to decide what we are. We're either going to be major league and support this team, or we risk losing them.''

Foster said he wants to commit the Rays to Tampa Bay for another generation — not just through 2027. He also wants to protect the economic and legal interests of St. Petersburg, which has spent about $150 million on stadium construction and operating costs.

In the past, Foster has questioned whether the Rays were marketing the team aggressively. But ticket discounts, a summer concert series and other efforts show the team is making a good-faith effort to draw fans, he said.

"I didn't always believe that, but I do now," he said.

Foster took a swipe at his Hillsborough counterparts, who have indicated they would help the Rays build a stadium there but are shy on financing details.

Based on the Miami Marlins' new venue, a retractable roof stadium could easily cost $600 million to $700 million. In similar markets, major league teams have put up roughly a third of construction costs, with public financing making up the difference.

"It's somewhat humorous to watch (Hillsborough County Commission Chairman Ken) Hagan and (Tampa Mayor Bob) Buckhorn kind of backpedaling a little bit because they were all wearing their finest trying to court the Rays to look over there,'' Foster said. "Now that it might actually happen, you got Ken Hagan saying he's not going to commit any taxpayer money to it, which is naive.

"And you have the mayor of Tampa saying he could come up with $100 million. But the private sector and the Rays have to come up with the lion's share. That's extremely naive."

Buckhorn was vacationing in North Carolina and could not be reached.

Hagan said, "I am extremely pleased that the mayor has started to realize that the status quo is a failed business model.''

But Hagan, who once said he was willing to cause the divorce between St. Petersburg and the Rays, denied any backpedaling on financing.

"Since 2010, I've been very consistent in stating that the Rays organization and the private sector will have to fund the construction of a new stadium irrespective of the area,'' Hagan said.

"There will never be another Raymond James sweetheart deal," added Hagan, referring to the stadium constructed for the Tampa Bay Buccaneers with taxpayer dollars.

Private investment could include naming rights, development rights and deals on parking garages, he said.

St. Petersburg City Council member Steve Kornell said it doesn't help the situation when Hagan and Buckhorn make "cute, little remarks" about recruiting the team to Tampa.

With the availability of money from the county's hotel bed tax, Pinellas is a better option than Hillsborough, he said.

"I think we're a major league market. They certainly want our television money,'' Kornell said. "I think we can offer them a better deal. We should all be working together, not against each other."

Council member Leslie Curran, who has butted heads with Foster on stadium issues, said the region can support a team because a new generation of fans is growing up and will eventually become ticket buyers.

But Curran also said she doubts that voters will agree to devote taxes to a new stadium.This story has been changed to reflect the following correction: St. Petersburg City Council member Steve Kornell said Pinellas County is a better location for a new baseball stadium because of funding available from a hotel bed tax. A story Tuesday incorrectly identified that funding source.