The veteran left-hander gave up seven runs in 2⅔ innings Thursday during a 12-11 loss to Colorado, his first outing after going on the IL because of a left index finger bone bruise.
Holland said he "did a fake injury" and that he's "not happy about that." He specified that his frustration is with the front office and not manager Bruce Bochy. He said, "they keep changing a lot of the things'' and "at the end of the day, I'm going to do whatever they ask me to do."
Farhan Zaidi, the team's president of baseball operations, told the San Francisco Chronicle later Saturday that the injury was legitimate.
"His use of the word 'fake' probably comes from him feeling he could continue to pitch with it," Zaidi said.
Bochy told reporters on Sunday that he spoke with Holland about his comments and expressed his disappointment that he aired his gripes publicly. He also said he planned to talk to the team about Holland's comments.
"You've got to do the right thing," Bochy told reporters. "I wish he'd have vented his frustration in a different way. I know Derek wishes he'd vented his frustration in a different way."
Zaidi said on Sunday that the Giants' 16-23 record has created frustration for the team and himself.
"If we're 23-16, I don't think we'd be sitting in this room right now. I understand it. I'm as frustrated as anybody. But again, I want us to have a culture of accountability where people are looking in the mirror and asking what they can do better," he told reporters.
The Associated Press contributed to this report.