LAS VEGAS — On the day the Knicks added Metta World Peace, they lost J.R. Smith — possibly for all of training camp and the first two weeks of the regular season.
Four days after announcing his new four-year, $24.7 million package, Smith underwent surgery yesterday in New York to repair a patellar tendon and a torn meniscus, both in his left knee, putting him out three to four months.
The Knicks said Smith had two chronic injuries that gradually worsened. According to a league source, the tendon was chipped.
Smith, who will be 28 in September, certainly won’t be ready for Day 1 of training camp in early October and could miss the season opener later that month.
The Knicks knew about the issue when the season ended and knew Smith would need surgery. Earl Smith, J.R.’s father, claimed the surgery was timed for mid-July during summer league and it had no bearing on his son hiding his injury during free agency.
A source said teams that inquired about Smith were made aware of his impending surgery. The Knicks had no major qualms about offering him a four-year deal because they considered it below market value and the maximum they were allowed to offer under Early Bird Rights.
The Post reported exclusively on May 23 that Smith played during the Pacers series with an undisclosed left knee injury, with a source saying it was swollen with fluid buildup. The source said at the time, “He shouldn’t have even been playing.’’
Earl Smith said the timing of the surgery was due to it being most convenient for the Knicks’ medical and training staffs, which were to return to Las Vegas so there would be no lapse in his son’s rehab. If part of the preseason would be sacrificed, so be it.
“That was the plan all along,” the elder Smith said.
However, only one Knicks trainer is in Las Vegas, along with team medical director Dr. Lisa Callahan, so the timing still seems odd.
Earl Smith said he expects his son to be back for the season opener.
“Knowing J.R., he will be,’’ Earl Smith said. “It’s a great possibility.’’
Smith’s knee issue helps explain his downturn in the playoffs as the fluid likely was caused by the wear and tear of his cartilage. The Post reported Smith had played with varying degrees of knee pain since March, but he did not miss a single game because of injury. He played 80 of 82 games, resting the final two with the rest of the starters.
According to a source, Dr. Callahan told Smith he had the option of having surgery in March, but he opted to play through it.
Earl Smith said his son was greatly affected by the injury — not by rumored postseason partying.
“His knee was swollen in the playoffs,’’ the elder Smith said. “He didn’t have the lift on his jumper. You can tell something was wrong. They had him keeping late nights.’’
The NBA’s Sixth Man Award winner averaged 22 points on 48 percent shooting in the regular season’s final month, but shot 33 percent in the playoffs. The Post reported in late May that Smith would have a drainage procedure on his knee.
Ironically, Chris Smith, J.R.’s younger brother who is playing for the Knicks’ summer league team, is coming off a torn patellar tendon. Chris’ injury was more severe, according to a source.
* Knicks rookie shooting guard Tim Hardaway Jr., wearing a black brace on the bench, sat out yesterday’s loss to the Bobcats because of his sprained left wrist and may be done for the rest of the summer league schedule. He sprained the wrist late in the first quarter against the Wizards and sat out the rest of the game. Hardaway hopes to play when the Knicks resume action either tomorrow or Thursday in the playoff round.
“Doctors said not to play, I chose not to play and not risk anything,’’ Hardaway said. “I don’t know [about the next game]. It’s up to the doctors what I can do. We’ll be in therapy [today], see how it goes. I really want to get back out there. If it doesn’t happen, it doesn’t happen.’’