Once a Celtic, always a Celtic apparently is not a thing in Boston.

Kyrie Irving will not play for the Nets in his scheduled return Wednesday night to TD Garden, prompting some Boston fans to call out their former All-Star guard around the arena he called home for two seasons.

Fliers of Irving with the caption “Coward” were posted on poles across the street, according to a tweet by ESPN reporter Malika Andrews.

Irving, who signed a four-year contract worth $142 million with Brooklyn over the summer to eventually team with injured signing Kevin Durant, currently is sidelined with what the Nets have described as a shoulder issue.

The Nets enter Wednesday’s game winners of five of their past six, with Irving appearing in only one of those games.

https://twitter.com/malika_andrews/status/1199778430574837760?s=21

https://twitter.com/NYPost_Lewis/status/1199798606913560576?s=20