“It’s been fun watching [the Celtics] play,” Ainge said by telephone from Salt Lake City this past week, before the Jazz were eliminated in the first round of the playoffs by the Mavericks. “Obviously, my focus is more on the Jazz, but it’s been fun to follow my old team and all my people back there. I still consider them and will always consider them — regardless of what happens from here on out — I’ll always consider them friends and family.”