The South Americans, needing games to be ready for next year's London Olympics, have signed contracts with overseas clubs.
Nocioni has joined former FIBA Americas League winners Peñarol in Mar del Plata, where he has been training during the lockout.
Splitter, who like Nocioni once played for Baskonia in Spain's top flight, has returned to the country to link up with Valencia Basket.
Nocioni, an NBA player since leaving Baskonia for the Chicago Bulls after the 2003-04 Spanish season, said: "This serves me as it serves everyone.
"I want to enjoy basketball.
"I couldn't let more time go by. The decision to play without insurance was taken so I wouldn't delay it any further.
"I cannot have the luxury of remaining without playing."
He was supposed to play at the 2010 FIBA World Championship but his club, the Philadelphia 76ers, forced him to withdraw citing medical concerns.
Nocioni played for Argentina this summer when they hosted the FIBA Americas Championship in Mar del Plata but missed three of the last four games because of injury.
Former Argentina boss Sergio Hernandez is the coach of Peñarol.
The decision to play in his homeland is being seen as a boon to the sport in the country but Nocioni, who turns 32 on November 30, said: "I don't feel like a star.
"I come to bring spirit.
"For the time being, I'm going to play in the Super 8 but that doesn't mean that I cannot continue in the Liga Nacional.
"This is a way to thank not only Peñarol but the league for giving us so many opportunities."
No one is happier than Hernandez.
"I am really excited," he said.
"I'm very happy and we must enjoy it. Another mad man for a club of mad men."
San Antonio Spurs youngster Splitter has decided to return to Spain during the lockout.
Valencia Basket announced on Wednesday they had signed Splitter, the MVP of the league two years ago when he led Caja Laboral (Baskonia) to an upset of Barcelona in the title series.