The altercation took place during practice Thursday. The 7-2, 240-pound Andriuskevicius, 20, spent Thursday night in intensive care in Bismarck, N.D.
''He has a skull fracture, severe concussion and a two-centimeter hematoma on the left side of his brain,'' Andriuskevicius' agent Herb Rudoy said. ''They've been monitoring him because they're concerned about seizures.
''From what I'm told, when he got hit unexpectedly, he went out cold instantly and fell right back on his head.''
The 6-6, 225-pound Storey has been suspended indefinitely while the NBA and NBDL investigate.
There's also been a police report written, according to Det. Dean Clarkson. But Clarkson said Andriuskevicius does not want to press charges, making an arrest unlikely. Clarkson said the investigation is pending.
''Awvee's a terrific kid,'' said his Chicago-based agent Mark Bartelstein. ''They had an altercation in practice, and it's really unfortunate.
''I know Awvee feels terrible about it. It wasn't a situation where he just attacked the kid.''
One source said Storey said something to Andriuskevicius, who went over to Storey and got punched.
''He's lucky he's not dead,'' Rudoy said. ''But I think he'll be fine.
''He won't be playing basketball for a long time. They have to be very concerned about his skull fracture healing.''
Rudoy expects Andriuskevicius to be released from the hospital in the next few days and return to Chicago for further examination.
Bulls general manager John Paxson called Andriuskevicius on Friday morning, and Bulls doctors are monitoring the situation.
Storey and Washington Wizards guard Gilbert Arenas were arrested over Memorial Day weekend in Miami Beach for refusing to obey police. The charges later were dropped.