Celtics coach Doc Rivers said following Friday’s win over Sacramento that center Kendrick Perkins has been fighting tendinitis in his left knee for some time and finally needed to sit down and rest it.

Rivers added that Perkins will likely also miss Sunday night’s home game against San Antonio. As for Nate Robinson, he sprained his left ankle in the second quarter and did not return. Rivers said if his ankle responds to treatment, he is still no better than ’50-50′ to play against the Spurs.