Blackley went 1-1 with a 14.21 ERA in seven games, including two starts, for the A's this spring before he was designated for assignment last Friday.
He allowed 27 hits in 12 2/3 innings for a .450 opponents batting average. Blackley was claimed off waivers from San Francisco last year on May 15 and went 6-4 with a 3.86 ERA in 24 games, 15 starts, with the A's.
He is 7-7 with a 5.37 ERA in 36 career Major League appearances, including 23 starts.
Goebbert spent most of the 2012 season at Double-A Corpus Christi, where he hit .304 with 23 doubles, six triples, nine home runs and 53 RBIs in 114 games.
He also walked 55 times on his way to a .399 on-base percentage. The 25-year-old left-handed hitter also hit .133 in 16 games with Triple-A Oklahoma City. Goebbert is a .285 career hitter with 31 home runs and 237 RBIs in 456 games over four seasons in the Minors.
Rick Eymer is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.