As the Marlins were wrapping up their nine-game West Coast road trip on Wednesday night, the finishing touches were being added to the roof panels of their new ballpark, in the Little Havana section of Miami.

In recent days, the three major roof panels were rolled into place, so now the west, center and east panels are all aligned and assembled.

"That was a major milestone," Samson said. "The roof should be done in the middle of July."

One of the major attractions of the 37,000-seat building is the retractable roof.

In design, the stadium will closely resemble Minute Maid Park in Houston. This week, Samson was in Arizona with the ballclub, and he observed the roof at Chase Field, home of the D-backs.

The trampoline-like lining the Marlins will have on their roof is similar to that at University of Phoenix Stadium, where the NFL's Arizona Cardinals play. A year ago, Florida officials took a tour of that building, and they actually walked on the flexible but sturdy roof lining.

The Marlins' new park is rapidly on the rise. It's more than 70 percent completed, and all stages of construction can be seen through the webcam.

As construction moves along, so do the discussions about a naming-rights partner.

Samson said that an announcement is expected "within weeks."

In the meantime, the "exterior skin" -- or cover -- is being applied to the roof, and that part is on schedule to be completed in August or September.

"[It will be finished] during the playoff drive," Samson said. "That gives us several months to work on certain stuff, like the stadium finishings, placement of art, completing bathrooms -- things like that."

Because of the excessive heat and unpredictable rain patterns, the Marlins anticipate keeping the roof closed for about 70 of their 81 home games in 2012.

But there's one game for which the organization would prefer to have the roof open -- the home opener.

"We've started talking about that," Samson said. "Ideally, it would be open, and at the end of the game, everyone would stay, and it would be the first closing of the roof. But it depends on weather."

The Marlins envision a spectacular grand opening.

"We want to do this amazing pregame ceremony, with flyovers and all sorts of stuff," Samson said. "But if the roof is closed, it would be done differently. It's going to be weather-dependent.

"It will, hopefully, be a nationally televised home game. It might be cool enough to have the roof open. We don't know yet."

What is known is that the opening and closing of the roof will take 11 minutes to 15 minutes, depending on wind conditions.

Ground rules have yet to be made, but the team doesn't anticipate opening or closing the roof once a game is in progress. And because playing conditions have to be the same for both teams, the roof won't be opened or shut in the middle of an inning.

"It would have to be after the bottom of the inning," Samson said. "But because it takes so long, generally, I'd say it cannot be closed during a game. It would be hard to have that time frame."

To get a better feel for the weather conditions, the Marlins have been working with the respected meteorologist Max Mayfield, the former director of the National Hurricane Center in Miami.

"We've had conversations with Max Mayfield, starting the process of asking his help to work with us to figure out a good formula of when the roof will be open, and when it will be closed," Samson said. "We've had good conversations. So that is in the works."

Since powerful Hurricane Andrew devastated the Miami area in 1992, all new buildings have to meet code, and the ballpark is capable of withstanding Category 4-force winds.

"Everything in this building meets code," Samson said. "That goes for our glass, the roof, everything. This will be a very safe building for our fans."

The interior of the roof will be a dark gray, which is expected to create favorable conditions for the players tracking the ball in the air.

Not long ago, Samson, team owner Jeffrey Loria, president of baseball operations Larry Beinfest, general manager Michael Hill and executive vice president of ballpark development Claude Delorme tested how a ball looks against the roof lining.

"We got samples from the steel manufacturer," Samson said. "We chose a dark gray color. It works perfectly. We put it up in the air, and we threw a ball up. It wasn't very scientific, but it worked."

Original:MLB.com