The Knicks have sorely missed the 2012-13 version of J.R. Smith during their 1-2 start, but their sixth man sees his five-game pot suspension as a blessing in disguise, giving him more time to shake off the rust from his knee rehab.

During Tuesday’s practice, Smith was the last one off the court, doing intense halfcourt and shooting drills while his teammates were in the locker room showering. Smith isn’t allowed in the arena during games.

After undergoing surgery to repair a torn meniscus and chipped patella tendon in mid-July, Smith played no basketball until October. He missed the entire preseason until the final game. His season debut will take place Sunday versus San Antonio, after he misses the home-and-home pair with Charlotte.

“It worked out kind of good, getting healthier, getting my mechanics down, focused on the knee getting to 100 percent as much as I can,’’ Smith said. “I’m trying to look at it in a positive way, getting more time to practice and prepare.‘’

Carmelo Anthony has looked like a lost puppy without Smith by his side. Smith has watched the three games at his home in Manhattan after being suspended under the NBA’s drug policy for failing three marijuana tests.

“I’m home, watching, observing, waiting for my turn,’’ Smith said. “I definitely see how much they missed me, but I’m just one person. It’s still a collective team effort and we’re just turning the ball over too much.’’

Mike Woodson has talked about starting Smith this season at shooting guard, but it appears likely he will at the outset come off the bench in last season’s role. So far, rookie Tim Hardaway Jr. has filled Smith’s sixth-man role.

“I’m ready. Whenever coach calls my name Sunday, I’ll be ready,’’ Smith said. “I wanted to play game 1, but unfortunately had to sit it out.’’

The NBA was slated to have an independent doctor examine Smith before the season opener to ensure he was healthy so the clock could start ticking on his suspension. However, Smith played the preseason finale and the NBA decided to “waive’’ the physical, according to Smith.