Marcus Smart reveals what he would have done differently with Celtics trade

Marcus Smart returned to TD Garden as a member of the Memphis Grizzlies on Sunday. (Danielle Parhizkaran/Globe Staff)It’s been almost eight months since the Celtics traded veteran stalwart Marcus Smart in a shocking, three-team swap that brought Kristaps Porzingis to Boston.

And while Smart’s anticipated return to TD Garden on Sunday was marked with outpourings of appreciation for the guard’s nine years of scrappy play, the Celtics’ fan favorite admitted that the sting of his surprise departure from Boston still bites at times.

During a pregame presser ahead of Sunday’s meeting between the Celtics and Grizzlies, Smart acknowledged that the NBA is a business — and that any player fixated on…