As part of the trade, the Bucks will have the right to swap first-round picks with the Bulls in 2010, sources said.
Initially, sources said the Bulls would get Kurt Thomas and Francisco Elson in return for Salmons. But Thursday morning, sources close to the process told ESPN.com that those plans changed when a deal that would have sent Warrick to another team fizzled.
The deal allows the Bulls to clear Salmons' $5.8 million salary off the books for next season. That puts them roughly $20 million under the cap next summer as the Bulls make a push to sign free agents like LeBron James, Dwyane Wade and Chris Bosh.
The deal gives the Bucks a shooting guard to replace the injured Michael Redd.
The Bulls held Salmons out of Wednesday's game at New York in anticipation of a trade. Salmons remained at the team's hotel and did not even accompany the Bulls to the arena, ESPNChicago.com reported.
The trade was expected to be announced Thursday, and a source told ESPN.com's Chris Sheridan there was a chance the deal would be expanded by the time it was finalized. But no matter what, the end result for Salmons will be a spot in the Bucks' starting backcourt alongside Brandon Jennings.
Bulls guard Derrick Rose was unaware of a potential trade before the Knicks game.
"Man, that's crazy thinking about John leaving," Rose said. "He just came here [in a trade with the Kings on Feb. 18, 2009]. But, it's the NBA. If he does get traded we'll definitely miss him, but [the season] must continue."
Rose said trades could affect the focus of a team, but he understands the nature of the business.
"It hurts your team a little bit," he said. "Like when you have a game right after [a trade]. But that's just how the NBA goes.
"People are going to be on your team, the next thing you look up and they could be gone. We'll definitely miss him if he does get traded, but it didn't go through yet, so he's still a part of this team."
Bulls coach Vinny Del Negro said it's tough telling a player not to get on a bus to go to a game.
"It's never easy," he said. "It's never fun. We're dealing with good character people.
"It's part of the business. You just have to deal with it, and move forward."
Del Negro said he wasn't at liberty to discuss the possibility of the Bulls acquiring McGrady.
"There's a lot of speculation out there," he said. "There's a lot of things that as an organization we're working on.
"My focus is on the game, and then I'll talk to [general manager Gar Forman and team president John Paxson] after the game and see where everything's at."
Del Negro doesn't anticipate any potential trades interfering with his team's concentration.
"I think if you've been in the league a while you understand the business part of it," he said. "It just comes with being a pro player. You just hope it works out for everybody [on] both sides. We want to keep our flexibility moving forward and add some if we can.
"Whatever happens is going to happen if it makes sense for both sides. I think players understand that. We have some younger players, but, overall we have good character guys like I've said. They know what their job is tonight. My job is to hopefully get them going early and get them in the game and get them involved."
Senior ESPN.com NBA writer Marc Stein and ESPNChicago.com reporter Nick Friedell contributed to this report.