Boston Celtics owner Wyc Grousbeck, whose family is in the middle of selling its controlling stake in the franchise, said Thursday that not only does he continue to plan to run the team for the next three years, but he believes they could repeat as champions this season. “It’s underway. There’s a lot of interest,” Grousbeck said of the sale on a conference call with reporters after a ceremony with President Joe Biden on the White House’s South Lawn to celebrate the team’s record-setting 18th NBA championship.