NEW YORK – Just as they got Metta World Peace, the New York Knicks lost J.R. Smith.

So the enthusiasm over landing a player General Manager Glen Grunwald said could be the Knicks’ “missing piece” was tempered by the news they could start next season without one of their key contributors.

Smith dealt with knee pain all season and wanted to deal with it his way in the summer.

When it wouldn’t get better, he agreed to surgery that could have him on the sideline when next season opens.

Smith had patella tendon surgery and an arthroscopy on his left knee to repair a tear in the lateral meniscus Monday.

Smith is expected to miss 12 to 16 weeks, meaning he may not be back until after the season starts. That could have been avoided if the surgery was done sometime sooner in the last two months.

“The decision is J.R.’s and he wanted to give it a chance to heal without having to have surgery and that’s perfectly understandable,” Grunwald said.

BUCKS: Milwaukee waived forward Drew Gooden and designated him as its amnesty player.

Gooden had two years and about $13.4 million remaining on his contact. He still receives the money but it doesn’t count against the Bucks for salary-cap purposes.

MAVERICKS: Rookie guard Shane Larkin underwent surgery to repair his broken right ankle.

Recovery time is expected to be about three months.

NUGGETS: Denver hired Arturas Karnisovas to serve as assistant general manager.

Karnisovas will help the new general manager, Tim Connelly, and the team president, Josh Kroenke, with day-to-day operations related to scouting and player personnel.

NETS: Coach Jason Kidd pleaded guilty to a misdemeanor drunken driving charge and was placed on interim probation a year after he smashed his Cadillac SUV into a utility pole on eastern Long Island.

In exchange for the guilty plea, Kidd agreed to speak to Long Island high school students about the dangers of drunken driving. If he fulfills his community service, his plea will be reduced to a violation, driving while ability impaired, when he returns to court Sept. 30.

SPURS: San Antonio agreed to a two-year contract with forward Jeff Pendergraph.

The 6-foot-9 Pendergraph spent the past two seasons at Indiana, mostly in a reserve role. He averaged 3.9 points and 2.8 rebounds per game last season with the Pacers, who reached the Eastern Conference finals.

HEAT: Miami designated Mike Miller as its amnesty player, a move that may save more than $30 million in luxury tax payments over the next two years.

Miller spent three seasons in Miami, helping the Heat win two titles and playing big roles in each playoff run. He started the last four games of this year’s NBA finals and made seven 3-pointers in Miami’s title-clinching Game 5 win over Oklahoma City in 2012.