Barnes reportedly turned down a $64 million offer before changing agents from Jeff Wechsler to Jeff Schwartz in late September. Since that point, the two sides have not made enough progress.
"He wanted to have some resolution to his extension discussions before the start of the season, which we completely understand," Myers said. "I think he just wants to focus on the games as they stand now. We've completed discussions, and we're not going to be able to reach a deal."
Myers declined to say how far apart the two sides are but said, "We had a lot of good dialogue, and we end the discussion on very good terms, very amicable."
The inability for both sides to reach a deal means Barnes will be a restricted free agent in July.
"We still can match any offer," Myers said of the team's chances of retaining Barnes via restricted free agency. "We can do five years. It puts us in a maybe stronger position."
Barnes spoke to media about his decision, saying he "wanted to put this to rest today," but doesn't see his contract situation being a problem for him on the court.
"No real worries. I approach the season the same," Barnes said. "The possibility of getting hurt, the possibility of getting X, Y and Z numbers, all that kind of stuff. It's all there whether you have a contract or not."
When asked if he wanted more control in a situation where the Warriors are pursuing big-name targets, Barnes said, "It's been a roller coaster since I got here. Dwight Howard, Kevin Love. Now they've won a championship, the Warriors are a desirable destination. So, it'll be nothing new."
The Warriors will receive their championship rings Tuesday night when they open the season by hosting the New Orleans Pelicans.