Anyone else notice that the owners of three of the four major Boston sports teams were sitting together at the Celtics playoff game the other night? C’s owner Wyc Grousbeck and wife Emilia Fazzalari picked a good game to host Patriots owner Robert Kraft and Ricki Lander, and Red Sox boss John Henry and his wife, Globe managing director Linda Pizzuti Henry. (Bruins owner Jeremy Jacobs, whose team played earlier in the day in Tampa, was MIA.) We’re told that Kraft, Lander, Grousbeck, and Fazzalari dined at Scampo before the game. . . . Meanwhile, former Patriots receiver Danny Amendola is still around despite signing with the Dolphins. Amendola stopped into the Back Bay Social Club over the weekend, having a salad and and chowder — and a glass of Pinot noir — with a pal. . . . Pats defensive back Duron Harmon and his girlfriend dined at Empire in the Seaport. . . . And 1980 Olympic hero Mike Eruzione celebrated his son’s 30th birthday party at King Seaport. . . . Clay Cook, a multi- instrumentalist in the Zac Brown Band, did a pretty fair rendition of the national anthem on Autism Awareness Day at Fenway Saturday. Cook will be back soon because the ZBB performs at the ballpark June 15 and 16.