The Celtics didn’t trade Marcus Smart — we are glad they didn’t, btw — and the C’s guard didn’t seem too worried that they would when he was spotted the other night in the Seaport. Smart, who’s sidelined with a hand injury suffered (he says) when he punched a hotel wall in LA, was at The Grand in the Seaport when rapper Rick Ross performed. Also there were Patriots lineman Shaq Mason and Kevin Schlehuber from CBS’s “Big Brother 19.” (Ross, we’re told, was drinking bottles of Belaire Rose Champagne with a picture of his face on the label.) . . . Meanwhile, Patriots receivers Julian Edelman and Danny Amendola were not far away. The pair were spotted together at Committee, the Mediterranean restaurant located in Seaport, and also at Strega Waterfront.