CREATE TABLE table_8731 ("Game" FLOAT, "Date" TEXT, "Opponent" TEXT, "Score" TEXT, "Location" TEXT, "Record" TEXT)

Who played against the Celtics on Sat. Feb. 23?
SELECT "Opponent" FROM table_8731 WHERE "Date" = 'sat. feb. 23'
SELECT "Opponent" FROM "table_8731" WHERE "Date" = 'sat. feb. 23'