X-rays showed a fracture in Ariza's right foot.
Ariza will see a specialist Monday to help determine a timetable for his return.
Ariza is a local boy who played basketball at Westchester High School, before going on to play for the UCLA Bruins. He left UCLA at age 19 after his freshman year of college to play professionally.
Ariza was a second-round NBA draft pick in the 2004 draft, picked up by the New York Knicks. He was the youngest rookie to play for the Knicks.
The Lakers traded for Ariza in November 2007. The Lakers sent Brian Cook and Maurice Evans to the Orlando Magic in exchange for Ariza.
Kobe and company host the Denver Nuggets on Monday.