Kevin Garnett and Paul Pierce arrived in Brooklyn on Thursday in gray suits, not Celtic green. Still, as they were introduced as the two most dynamic additions to the Nets, it was hard not to recall all the toughness they demonstrated for six years together in Boston.

Now, in what may be the final chapter of their N.B.A. careers, they hope to make the Nets a viable contender for an N.B.A. title. If nothing else, they will be an irksome presence for many Knicks fans, for whom anything Celtic, even former Celtic, is irritating.

Garnett and Pierce were joined on a stage at Barclays Center by a third player acquired from the Celtics, the veteran guard Jason Terry. Not in attendance was the veteran forward Andrei Kirilenko, the Nets’ fourth acquisition of the summer. Whether the four can combine with Deron Williams, Brook Lopez and Joe Johnson to push aside the Miami Heat will be determined soon enough, but the words “champion,” “champions” and “championship” were said a combined eight times in the first five minutes of the news conference.

General Manager Billy King used “championship” three times in answering one question.

“It’s the only reason we all gathered here,” Garnett said. “You don’t gather to win a playoff series or put a team like this together to get to the conference finals.”