According to Jason Thompson via twitter:

Jason Thompson
jtthekid Jason Thompson
Yessssirrr!! RT @Biggame1190: @jtthekid JT, you gonna play tonight big guy?
That emphatic, “Yessssirrr!!” is vintage Jason Thompson.  I spoke to Thompson following the Spurs game on Friday and he was itching to play and thought he would be ready to go tonight.  Now we know for sure.  Thompson missed the previous two games with a sprained right ankle.  There is still no confirmation on whether Thompson or Dalembert will get the call to start alongside rookie DeMarcus Cousins.