Allen Iverson did not show up for his team's BIG3 game in Dallas on Sunday, an absence that was unexpected for the fledging 3-on-3 basketball league.

"We had no advance warning and do not have information as to all the circumstances surrounding his absence. The league is launching an investigation to gather all the facts and then will make an informed, official statement," the league said.

Basketball Hall of Famer Allen Iverson serves a player and coach for Three's Company of the BIG3 league. Mitchell Leff/BIG3/Getty Images

Iverson is one of the league's marquee names, which kicked off in June. The Basketball Hall of Famer serves as player and coach for Three's Company.

Iverson has played sparingly during the season. He sat out the team's game in Philadelphia on July 16, a homecoming for the former 76ers legend.

BIG3, co-created by rapper Ice Cube, is composed of eight teams that travel each week to a different city. Other notable names who play or coach in the league include Chauncey Billups, Kenyon Martin and Julius Erving.