J.R. Gidden’s postseason is over — with the Utah Flash, at least. The Celtics  rookie led the Flash to the NBDL Finals before losing to the Colorado 14ers on Friday night, 123-104. Giddens, who was assigned to the Flash in March, posted 17 points , 15 rebounds, and 5 assists in the loss. He averaged 17.2 points (57.8% FG) and 6.3 rebounds during the D-League playoffs. Giddens was selected by the Celtics with the 30th pick in the 2008 Draft.