"He said one too many things, so that was a short night for him," Mariners manager Eric Wedge said.
Bradley was tossed by plate umpire Mark Buchanan in the bottom of the third inning after barking about a called third strike.
Brendan Ryan hit a tying three-run homer in the seventh for the Mariners, but Milwaukee produced the game's final run with two singles and a sacrifice in the top of the ninth.
Rickie Weeks doubled three times, and both George Kottaras and Casey McGehee tripled and doubled for the Brewers. Weeks raised his spring training batting average to .448 (13-for-29) and scored a run.
"He is swinging real well," Brewers manager Ron Roenicke said. "He had a couple of games there where he didn't but he can turn it around and show what he did today. Plus he's forcing it by taking some extra bases, too. Not like they're automatic doubles."
Yovani Gallardo started for the Brewers and gave up a run on three hits in 4 2/3 innings.
"The last couple of starts, I'll really try to put everything into it," Gallardo said.
Mariners LHP Nate Robertson had arthroscopic surgery on his left elbow Wednesday in Los Angeles. He had three loose bodies removed from the elbow and is expected to rejoin the club Thursday to start rehabilitation in the form of range-of-motion exercises. ... Thirteen-time All-Star Ken Griffey Jr. arrived Wednesday to start his new job as special consultant to the Mariners' front office. Also, former All-Stars Jay Buhner, Edgar Martinez and Dan Wilson are in Mariners camp as guest instructors. ... Brewers OF Logan Schafer will undergo surgery for a broken right thumb Thursday and is expected to be out four to six weeks. ... Brewers reliever Takashi Saito, who is from Sendai, Japan, went to pick up his wife and children at the Phoenix airport Wednesday after he pitched. Saito's relatives in Japan are all accounted for.