After not securing a Major League deal, Kobayashi moved to the Hanshin Tigers in 2011 and posted a 3.00 ERA with 45 strikeouts and 19 walks in 39 innings, then spent the 2012 season pitching in Japan's Industrial League.
The Kobayashi signing comes a day after the team signed veteran infielder Bill Hall to a Minor League deal, putting its list of camp invites at 64.
Alden Gonzalez is a reporter for MLB.com. Read his blog, Gonzo and "The Show", and follow him on Twitter @Alden_Gonzalez. This story was not subject to the approval of Major League Baseball or its clubs.