Upton is 3-for-20 over his last five games.
"I feel fine [physically]," Upton said. "Obviously I've struggled the last couple of days so Gibby wants to give me a day to rest. I hate being out of the lineup, but it's up to him. It's his decision, ultimately, and he felt like today was the day to give me off. There's not much I can do about it."
When he was asked about Upton being out of the lineup, Gibson declined to say why.
"He doesn't have to play every day," Gibson said. "Just different lineup today. That's the reason. He's not in the lineup, he'll be in a different capacity. He's available for sure."
Gerardo Parra got the start in right field.
In the nine games prior to his five-game slump, Upton was hitting .419.
"The last few days I've struggled, but before that I was feeling pretty good at the plate," he said.