Going to a Phillies game or the Charli XCX concert this week? Here’s what to know about stadium workers on strike.

As Phillies fans file into Citizens Bank Park on Monday evening, hoping to see their team clinch the division, Aramark employees who work at the stadium’s food, drink, and retail establishments will be on the picket line.

Hundreds of unionized concessions workers who staff vendors at the South Philadelphia sports complex are on strike as they seek to negotiate new contracts with their employer, Aramark. The union is also asking fans not to buy food and drink inside the stadium.

Aramark has a contingency plan in place to deal with the absence of workers, according to spokesperson Debbie Albert.

The workers’ union, Unite Here Local 274, has been negotiating for better wages and benefits for Aramark employees at Citizens Bank Park, Lincoln Financial Field and Wells Fargo Center. Many of them work at more than one stadium, and the union is seeking standard employment conditions across all three venues.

All three stadiums have been on strike watch since Sept. 6, when workers of the Linc voted to authorize a strike. On Sunday the union called for a strike across the three stadiums starting Monday and did not say when the work stoppage would end.

The Phillies anticipate no disruption in services to fans, a spokesperson said Monday morning. Ticket sales for each of the team’s next three games against the Cubs have topped 40,000.

Efforts to reach a spokesperson for Comcast Spectacor, the company that owns the Wells Fargo Center and the Flyers, were not immediately successful on Monday morning.

If you’re headed to a Phillies game or the Charli XCX concert this week, here’s what you should know:

The Phillies play the Chicago Cubs at Citizens Bank Park tonight at 6:40 p.m.

The game is the first in a three-game series. The Phillies will also host the Cubs at 6:40 p.m. Tuesday and 6:05 p.m. Wednesday.

The strike is happening across all three sports stadiums: Wells Fargo Center, Citizens Bank Park, and Lincoln Financial Field, and several events are scheduled for this week.

Events at the Wells Fargo Center include a Charli XCX concert Wednesday. The Flyers, still in preseason, play at home on Thursday against the New York Islanders and on Saturday against the Boston Bruins.

The next Eagles game at the Linc is scheduled for Oct. 13 against the Cleveland Browns.

“The vast majority of the concessions at all three stadiums” are staffed by Aramark employees, according to Unite Here’s attorney, Dermot Delude-Dix.

At Citizens Bank Park, the union also represents retail workers who are also on strike. The union does not represent those workers at the other two stadiums.

In total, Local 274 represents some 1,500 Aramark workers employed at all three stadiums.

As of Sunday night, spokesperson Albert said the company has a contingency plan in place to deal with the absence of workers.

The union is encouraging those attending the game to support the strike by “not patronizing Aramark and choosing to tailgate or grab dinner elsewhere ahead of the game instead.”

Teamsters Joint Council No. 53 has sanctioned the strike, meaning that unionized delivery drivers can refuse to make deliveries to Aramark.

Amid the contract negotiations, each stadium set up a separate delivery entrance for Aramark-related deliveries, Delude-Dix said. The union is monitoring those entrances, asking delivery drivers not to cross the picket line.

“Since this morning, over a dozen deliveries have been turned away by our pickets at Citizens Bank Park and the other stadiums,” Delude-Dix said. “Food or beer or what have you has arrived at the stadium and then the driver has refused to cross the picket line.”

Phillies fans have long been able to bring in their own food into the ballpark. Attendees should be aware of bag policies implemented this year which restrict most bags that are not clear.

Unopened plastic bottles containing nonalcoholic beverages are allowed, as well as juice containers in soft packaging, and baby bottles.

Fans are not allowed to bring alcoholic drinks into the stadium, and glass bottles and cans are also prohibited.

The Wells Fargo Center does not allow fans to bring in any outside food or beverages, including water.

Staff writer Jeff Gammage contributed to this article.