"My gosh, I hated to tell [manager Bob Melvin] this morning that it just wasn't feeling good," Davis said. "When he asked me if I wanted to play Sunday, I said, 'Of course,' because the competitor in me, I can't pull myself out. But I knew during that game when it got worse that it was something a little more serious."
Davis' elbow feels fine, he said, but several of his left fingers are numb as the result of nerve irritation, and he was expected to see a doctor on Tuesday night. The shorthanded A's were also without cleanup man and third baseman Danny Valencia, who is dealing with a stomach bug, for the Interleague series opener.
"It's just constant numbness," Davis said. "I've never had a nerve damaged, so it's hard for me to know what I'm supposed to feel. I know with activity it gets worse. I just have to see day by day, obviously. Hopefully, the doctor has some good news."
Davis, 28, enjoyed the first seven seasons of his professional career with the Brewers, after they selected the Cal State Fullerton product in the seventh round of the 2009 Draft. He made his Major League debut in 2013 and took advantage of unforeseen playing time in left field when Ryan Braun was suspended for violations of MLB's Joint Drug Prevention and Treatment Program.
Davis busted out for a combined 49 homers in the following two seasons, remaining in left field even after the return of Braun, who moved to right field.
"Khris earned it," Brewers manager Craig Counsell said. "He was not a high Draft pick, so he had to go and perform, and he performed. He earned his promotions to the next level. He earned his way up here and then he had to earn at-bats."
The A's targeted Davis' right-handed power bat in the offseason, acquiring him on Feb. 12 in exchange for a pair of prospects. Davis has since totaled 14 home runs and 36 RBIs for Oakland, batting .234 over his first 54 games while settling into his new home.
"I would say it's a little looser atmosphere here," he said. "I like it. I'm just getting more comfortable with a new situation and the organization.
"Different vibe, different individuals, different unit. Different stories and different personalities."