CLEVELAND – Imagine the indignation of fans if Derek Jeter showed up at the Garden for a Knicks-Celtics game wearing a Celtics hat.

Now you get the idea of this town’s reaction to the Cavaliers’ LeBron James sitting behind home plate for the Indians’ Game 1 of the ALDS wearing the hat of his favorite team, the Yankees.

Talk radio heard some venom yesterday after James’ public-relations gaffe. The Indians, though, didn’t seem that bummed.

“Hey, he’s a Yankee fan,” said C.C. Sabathia, a good friend of James. “I really don’t feel anything about it. I knew he was here, but I didn’t know he had his Yankees hat on until my family told me. He is what he is, a Yankees fan.”