Marc Gasol, a center for the Memphis Grizzlies, will start practice on Tuesday with his older brother set to join on Thursday.
Barcelona says the Gasols can practice with their former club "while the NBA lockout lasts."
The Los Angeles Lakers' Pau Gasol told Catalan radio RAC1 that "Barca would be my first option to consider" playing for if the NBA season is canceled.
Pau Gasol called Barcelona the best basketball team in Europe, explaining his decision on his Twitter page Tuesday.
"For me @FCBarcelona is the best team in Europe. @MarcGasol and I are here to contribute even more to a group which is already excellent," he wrote.
It was a sentiment that Marc Gasol also shared with his Twitter followers earlier Tuesday morning.
"I start training today with Regal Barça!! So proud of being back home and train along with the best European team!! #FCBarcelona," he wrote.
Information from The Associated Press was used in this report.