"I felt something for a couple of days," Davis said. "I just felt like it was just little, that I could play through it.
"Just nagging. Just figure it's not progressing like I would want it to."
Davis will be evaluated again on Saturday, and it was not immediately clear if he will require a stint on the disabled list.
The 32-year-old Davis is hitting .281 with a homer and four RBIs in 26 games. He has split time between left field and designated hitter, starting frequently against left-handed pitching.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.