Security always is a concern at the All-Star game, but there might be a reason for extra vigilance when the game is played tonight at Chicago’s U.S. Cellular Field.

That’s because the stadium has a history of unruly fan behavior.

Earlier this season, a fan who had been drinking heavily left the stands and attempted to tackle Laz Diaz, an American League umpire.

In September, Tom Gamboa, a first-base coach with the Kansas City Royals, was attacked by a man and his son.

After both incidents, Major League Baseball asked the Chicago White Sox to provide more security at games, and the team took action immediately to try to prevent further incidents.

Tonight, the host White Sox are hoping all of the action will take place on the field.

Baseball will lend a hand by providing additional security and support. Kevin Hallinan, baseball’s security chief, arrived in Chicago last week to supervise the security effort, which will involve teams from the FBI, the Illinois State Police, the Cook County Sheriff’s Department and the Chicago Police Department.

Fans will see the presence of security, but the focus will be on the game itself, Hallinan said.

“We don’t want this to become a security event,” he said.

Command posts will be set up at the stadium. And the security forces will meet while the game is being played in case adjustments have to be made.

Scott Reifert, director of public relations for the White Sox, said the franchise tried to strike a balance between being a secure place for a game and giving fans the proximity to the players.

“It’s a ballpark and people want that atmosphere when they go to the game,” Reifert said. “But you want a safe environment for the people.”