Mijares produced a 4.22 ERA in 60 appearances with the Giants last year. The 29-year-old has made 237 of his 324 career appearances for American League clubs.
After claiming him off waivers from the Royals during the 2012 season, the Giants saw Mijares post a 2.55 ERA in 27 regular-season appearances and then prove to be a valuable situational lefty during a postseason run that concluded with the club's second World Series title in three years.
In the 78 appearances he combined to make for the Royals and Giants in 2012, Mijares posted a 2.56 ERA and limited left-handed hitters to a .211 (26-for-123) batting average.
Mijares was never able to rekindle that success last season. Right-handed hitters batted .360 (40-for-111) with a .421 on-base percentage against him. More troubling was the fact that he allowed left-handers to hit .276 (27-for-98) with a .343 on-base percentage.
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.