The Braves will miss Varvaro, whose 2.29 ERA in 42 appearances is the second-best mark in the bullpen this season, but Schlosser's promotion temporarily fills a hole in the Atlanta bullpen created on Tuesday night.
David Hale entered Wednesday having pitched five innings in the past three days, including three frames in relief of starter Mike Minor on Tuesday night.
"He was pitching good, and we kind of needed a long guy," Gonzalez said of bringing up Schlosser, who is a starter for Gwinnett. "So we needed a kind of a guy that could give us some innings, some length, and so he's the guy."
Schlosser began the year with Atlanta, compiling a 4.50 ERA in 12 innings out of the 'pen before he was optioned back to Gwinnett. He owns a 3.65 ERA and opponents are batting .238 against him in 15 International League outings (13 starts).
Schlosser also joined the big league club as the 26th man during the Braves' doubleheader in Philadelphia on June 28, but he did not see any action.
The side-armer has been especially effective of late, notching five quality starts and a perfect inning of relief in his past six trips to the hill. He is 3-2 with a 1.91 ERA, a 1.15 WHIP and 2.45 walks per nine during the stretch, showing progress in a season where his 3.7 walks per nine is on track to be his worst rate since he was drafted in 2011.
"Overall, I've been pretty good, just trying to get better," Schlosser said. "I still work on my changeup a lot, and I think it's gotten better and better each time out."
Mark Bowman is a reporter for MLB.com. Joe Morgan is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.