CHICAGO -- Visiting hitters won't have their home runs thrown back onto Wrigley Field until May 11, at least, as the Cubs announced the stadium's famous bleachers won't be open for the first month of the 2015 season.

The target date is May 11 for the left field bleachers and late May for the right field bleachers, Cubs president of business operations Crane Kenney said at the team's convention Saturday.

The bleacher reconstruction is part of the first phase of a $375 million renovation of the famous stadium, which celebrated its 100th birthday last season. Wrigley Field currently is a construction zone, and those who walk by can see the progress of the bleacher areas.

In late November, Kenney broke the news to a group of Cubs bloggers that the bleachers wouldn't be ready for opening night, a Sunday night game on April 5 against the St. Louis Cardinals.

"We're going to do it right," Kenney said. "If we miss the month of April, we do."

There are about 5,000 bleacher seats at Wrigley. While the team is only rebuilding the left- and right-field sections, the center-field section won't be open until the left-field one is finished because of safety concerns.

There are only 12 home games in April, which made the opening month doubtful for opening, considering the current status of the bleachers. There will be at least 15 games affected by the construction.

Workers at Wrigley Field continued construction on its famed bleachers earlier this week. Courtesy Jon Greenberg

Bleacher season-ticket holders, which make up about 2,000 seats, have three options for the 15 games prior to May 11, according to Cubs vice president of sales and partnerships Colin Faulkner: full refunds, account credits or relocation to other seats. For fans who don't respond to the Cubs by the end of January, account credit is the default option.

Because of the concerns, the team didn't put bleacher tickets in its mini-plans. Single-game tickets haven't gone on sale yet.

Kenney said the fabricated steel for the bleachers will be delivered in early February. The right field delay is a little longer than the left field side, Kenney added, because the team was waiting for sewer work to be done on Sheffield Avenue.

The bleacher cement will take about a month to solidify, Kenney said, so it might look like the bleachers are ready well before they actually can be used.

Construction around the park will be a fact of life for the Cubs, and their fans, during the four seasons.

"We're rebuilding a 100-year-old facility, there's going to be inconveniences for everybody," Kenney said. "It's just a reality."

The Cubs unveiled rebuilt bleachers in 2006, but this process is a little more complex partly due to the fortifications for new video boards, a major technological step forward for the historic ballpark.

The left-field video board, situated on the back wall of the left-field bleachers, will be up and running before the bleachers are finished, according to the team. Crain's Chicago reported that Daktronics will be handling the boards.