Professional indoor lacrosse is returning to Philadelphia. A press conference on Thursday will announce that Comcast Spectacor is acquiring a National Lacrosse League franchise, according to a person familiar with the situation.

The source says that the Philadelphia franchise won't begin play the upcoming season, which will run from December until early June. Details on the team's name and when it will begin play will be laid out at the press conference.

The new Philadelphia team presumably will begin as an expansion franchise, the source said.

Philadelphia has been a major player in indoor lacrosse (also known as box lacrosse). The Philadelphia Wings had a franchise for 28 seasons. The Wings were among the four teams that played in the what was known as the Eagle Pro Box Lacrosse League, which began play in January 1987. The league was renamed the Major Indoor Lacrosse League in 1989 and then the current National Lacrosse League in 1998.

The Wings, who won six league championships, relocated in July 2014, becoming the New England Black Wolves and playing at Mohegan Sun Arena in Uncasville, Conn.

There are nine teams in the NLL, although San Diego will begin as an expansion franchise in December of 2018.

The NLL, which has its league office in Conshohocken, has stated in the past its desire to have a team in Philadelphia. Nick Sakiewicz, the NLL commissioner, is the former CEO and operating partner of  Major League Soccer's Union and is very familiar with the Philadelphia market.