SAN ANTONIO

In his first meaningful act as the Nets’ interim head coach, P. J. Carlesimo sat down with Deron Williams and laid out his mission, a broad outline for leading the Nets to success.

“I told him exactly what I needed him to be,” Carlesimo said Tuesday. “I needed him to be Deron Williams.”

This is more complicated than it sounds.

The Nets need the Deron Williams who led the Utah Jazz to the Western Conference finals in 2007, the Deron Williams who became an All-Star at 25, the Deron Williams who was, not long ago, widely regarded as one of the two best point guards on earth (along with Chris Paul).

The Nets need the Deron Williams they thought they had acquired from Utah on Feb. 23, 2011, the one whose mere presence could reinvigorate a franchise, change perceptions, inspire greatness, energize a borough, start a new era.