Davis missed a layup inside the final minute of the second quarter and collapsed to the floor after landing. He was slow to get up, clutching at his groin area while play continued on the other end of the court, and did not return to the game after halftime.
The best-of-seven series is now tied 2-2. Game 5 is on Tuesday.
Davis came into the game playing on a sprained left knee that he suffered in Game 3, landing awkwardly after executing a chasedown block on Suns star Devin Booker.
He averaged 34 points, 10.5 rebounds, 3.5 assists and 2.0 blocks in Games 2 and 3 of the series to give the seventh-seeded Lakers a 2-1 lead over the No. 2 Suns. Davis finished Game 4 with six points on 2-for-9 shooting with four rebounds in 19 minutes.
Kyle Kuzma started the third quarter in Davis’ place and finished with 11 points on 4-for-11 shooting.
The Lakers also played without Kentavious Caldwell-Pope, who was ruled out prior to the contest.