While Gonzalez, 31, was 0-0 with a 7.71 ERA in three starts for the Mets this season, Yost plans to use Gonzalez in a relief role.
"He's a good guy, hard worker," Yost said. "He'll fit right in."
Gonzalez was designated for assignment by the Mets on Thursday following his start against the Phillies. He began the season at Triple-A Norfolk, where he was 1-2 with a 3.03 ERA in six starts.
Gonzalez, who was originally signed as a non-drafted free agent by the Cubs in 1991, has pitched in the Majors for the Cubs, Devil Rays, Red Sox and Mets.
He has a career record of 26-33 with a 4.92 ERA in 110 career appearances, 82 of which were starts.
The Brewers announced after Saturday's game that they optioned right-hander Carlos Villanueva to Double-A Huntsville.
No worries here: Though closer Derrick Turnbow suffered his second blown save in Friday's win over the Phillies, he did earn his second win of the season.
More importantly, Turnbow said the blown save will not affect his confidence whatsover.
"You have to trust your stuff and come back ready to go," said Turnbow, who has 14 saves this season. "You can't let a blown save hurt you."
Turnbow gave up two runs on Friday, but Yost isn't concerned about his closer.
"They're good fastball hitters," Yost said of the Phillies, specifically Bobby Abreu, Pat Burrell and Ryan Howard. "Not only are they good hitters, but they hit good pitches."
On the comeback trail: Pitcher Rick Helling threw about 30 pitches in a simulated game on Saturday.
"It went all right," said Helling, who has been out since early April with an elbow injury. "I was expecting better, but it was all right. I got through it."
Yost is taking a wait-and-see approach.
"He looked OK," Yost said. "He threw the ball good. We'll see how he rebounds after this one."
Good matchup: Geoff Jenkins has fared incredibly well against the Phillies in the Brewers' four wins this season.
In those four games, Jenkins is 9-for-16 with one home run and nine RBIs.
"It's one of those things," Yost said.
Stepping in: Yost said that left-hander Jorge De La Rosa will start Tuesday's game at Pittsburgh. De La Rosa is 2-0 with a 6.75 ERA in 15 appearances.
"I'm just going to give De La Rosa a shot now," Yost said. "He's been pitching good. We made up our mind on De La Rosa before the Gonzalez trade."
Extra bases: The Brewers are 10-3 against the National League East this season entering Saturday's play. ... They are 13-3 this season when their starting pitcher goes at least seven innings. ... The Brewers lead the NL with 68 home runs.
Next up: Left-hander Dana Eveland (0-1, 8.22 ERA) will oppose Phillies righty Ryan Madson (4-3, 5.98) in the finale of the three-game series on Sunday at 12:35 p.m. CT.