Gross, 31, spent the entire season with the A's, but received sporadic playing time. He hit .239 with one home run and 25 RBIs in 105 games (54 starts). The outfielder carried a .309 average through June, but hit a dismal .188 over his final 68 games and was not expected back next year.
Playing time also came at a premium for Larish, who was recently sent home with a broken toe from winter ball in Venezuela, where he was 1-for-13 in four games with Leones del Caracas before the injury.
The 28-year-old Larish, claimed off waivers from the Tigers on Aug. 3, showed flashes of power but ultimately struggled with consistency at the plate, going 10-for-58 (.172) with two home runs and eight RBIs in 23 games (14 starts) during two stints with Oakland.
Seven of those starts were in left field, marking his first appearances in the outfield in the Majors or Minors. Larish also saw a dose of action at designated hitter, as well as the infield corners when third baseman Kevin Kouzmanoff and first baseman Daric Barton were injured.
Meloan, meanwhile, missed the entire season after undergoing Tommy John surgery on his right elbow on March 30. Fellow hurler Souza split his season between Double-A Midland and Sacramento, but was sidelined the final month with a stress fracture in his right elbow.
Souza went 2-2 with six saves and a 3.38 ERA in 28 relief appearances for Midland and proceeded to tally an 8.00 ERA in five outings with the River Cats.