Acquired in the Dan Haren deal over the winter, Gonzalez, 22, joined the A's for the second time this season. He opened the year in the Minors but was called up to Oakland on May 30 and batted .274 in 39 games before the All-Star break. He slumped after the break, batting .204 in 38 games before being sent back to Triple-A on Aug. 27.
"I totally changed my mechanics -- changed mentally, too," Gonzalez said of the cause of his struggles. "I was anxious at the plate, swinging at bad pitches. My swing had changed. I was swinging and missing pitches that I never miss. I was getting in bad position with two strikes too often.
"I went down to relax and do what I did early in the year."
Gonzalez, one of the game's top-rated prospects entering the season, batted .406 with two home runs and eight RBIs in eight Pacific Coast League playoff games.
"If you're in the Minors and you've never been in the Majors, it's OK," Gonzalez said. "But once you've been in the Majors, you realize how badly you want to be back here."
For his late-season run, Gonzalez was named co-PCL playoff MVP with Denorfia, who also returned for a second stint with the A's. He was on Oakland's Opening Day roster and batted .260 with six RBIs in 25 games before going on the disabled list retroactive to May 7 with tightness in his back.
Reinstated from the DL and optioned to Sacramento on July 19, he batted .302 with 20 RBIs in 45 regular-season games with the River Cats. He then hit .486 with four home runs, six RBIs and 12 runs scored in eight playoff games, helping Sacramento to its fourth PCL championship in the past six years.
Oakland's other outfielders are Ryan Sweeney, Rajai Davis, Jack Cust, Aaron Cunningham and Travis Buck.
"I know there will be three of them in there every day," Geren said with a laugh. "Every one of them deserves a shot to get some at-bats."
Geren suggested that Buck, who was called up from Sacramento on Tuesday and was in the leadoff spot Wednesday, will see as much time as anyone down the stretch.
"I want to give him a good look the last couple of weeks," said the skipper.