Kansas City Royals left-hander Aaron Laffey and Detroit Tigers second baseman Will Rhymes became free agents after their teams declined to offer 2012 contracts.
Clubs had until midnight EST on Monday to offer contracts to unsigned players on their 40-man rosters.
In the hours before the deadline, Los Angeles Dodgers outfielder Tony Gwynn Jr. agreed to a $2 million, one-year contract. Also getting one-year deals were Houston catcher Humberto Quintero ($1 million), Toronto right-hander Jesse Litsch ($975,000), Blue Jays right-hander Dustin McGowan ($600,000), Los Angeles Angels pitcher Jerome Williams and Milwaukee Brewers catcher George Kottaras.
Failing to offer contracts is a way clubs can avoid going to salary arbitration with players who otherwise would be eligible.
Russell Martin was cut loose by the Los Angeles Dodgers at the deadline last year and wound up hitting 18 home runs as the New York Yankees' primary catcher.