Anderson motioned to the dugout for help after running toward the third-base line and bending forward to pick up Jonny Gomes' chopper.
Following a visit from manager Don Mattingly and trainer Stan Conte, Anderson walked off the field under his own power.
Anderson left trailing 3-2. He allowed five hits, three runs, two walks and struck out two in 2 2-3 innings.
Chin-hui Tsao took Anderson's place.
Anderson hasn't missed a turn in the rotation this year despite seven trips to the disabled list in his career.
The Dodgers announced Anderson's diagnosis in the bottom of the sixth. He will be reevaluated on Wednesday.