Veteran pitcher Livan Hernandez and catcher Yorvit Torrealba refused outright assignments to Triple-A Nashville and elected free agency. They would have hit the open market, anyway, after the World Series.
Sanchez, 25, a converted catcher, would have been a six-year Minor League free agent had the Brewers not added him to the roster.
The Venezuelan-born Sanchez had a 1.62 ERA in 52 relief appearances between Double-A Huntsville and Triple-A Nashville in 2012. He logged 11 saves at Huntsville before his promotion and, overall, surrendered only two home runs in 71 2/3 innings.
The Brewers signed Sanchez in Jan. 2011, after he was released by the Phillies. That team converted him from catcher to pitcher beginning in 2009, and in 132 Minor League mound appearances, Sanchez has a 3.34 ERA.
The Brewers will clear two more roster spots when pitchers Shaun Marcum and Francisco Rodriguez reach free agency after the World Series, but those spots will be claimed when pitcher Chris Narveson and first baseman Mat Gamel are reinstated from the 60-day disabled list.
One other player on the 60-day DL, shortstop Alex Gonzalez, would be a free agent if the Brewers decline his 2013 option.