Collison worked out with the Warriors on Wednesday and was expected to do the same Thursday.
Collison, 34, is best known for his time with the Pacers, but retired at the end of the 2018-19 season. He has been considering a return to the NBA over the past year.
Meanwhile, the Warriors are also looking to add some veteran depth behind Curry and a presumably healthy Klay Thompson.
Collison has also spent time with the Kings, Clippers, Mavericks and Hornets. He averaged 11.2 points and 6.0 assists in 76 games in his last NBA season with the Pacers.
“The Warriors badly need backup point guard help, and a steady veteran like Collison is ideal,” wrote Dalton Johnson of NBC Sports Bay Area. “He knows how to run an offense and is a scoring threat as a 3-point option.”
Chris Haynes of Yahoo Sports first reported Collison would work out with the Warriors.