Kevin Garnett had been away from the Nets for so long that some teammates, and even coach Jason Kidd, joked with him prior to Saturday night’s game against the 76ers that he should be treated like a rookie. And despite being in the 19th year of a Hall of Fame career, Garnett admitted to feeling nervous before stepping on the floor. But after missing 19 games over the last five weeks because of an ongoing bout with back spasms, Garnett looked as if he hadn’t missed a day, let alone a month. Moving fluidly, Garnett finished with 10 points on 5-for-6 shooting to go with four rebounds, an assist and a block in 13 minutes as the Nets earned a 105-101 victory over the hapless Sixers. “I’ve been working my [butt] off to get back to where I’m at,” Garnett said after coming through the game with no further back issues. “Obviously I’m not to where I want to be but I felt good, I felt strong. … It’s been a journey to get back to this point, so I’m just trying to contribute at this point.” The win improved the Nets (42-34) to 16-5 in their past 21 games and snapped the team’s three-game road losing streak, but the only thing that mattered was the way Garnett felt in his first action since Feb. 27. And with the way Garnett looked against the 76ers (17-60), his return to the floor can only be considered an unqualified success. In fact, it looked like the time off actually gave Garnett some added energy in his legs, as the future Hall of Famer played as well as he has in any game this season. He moved freely and easily at both ends of the floor and found an immediate rhythm within the offense and with his jump shot. “I thought he was great,” coach Jason Kidd said. “He looked like he didn’t miss a day.” Garnett’s biggest highlight of the night came in the second quarter, when he turned back the clock by setting a screen for Deron Williams and then rolling hard to the basket, leaping in the air to catch a lob pass from his point guard and slamming it home with two hands. “He has fresh legs,” Williams said afterward with a smile. Everyone was smiling in the locker room afterward, including Garnett. Famously competitive, Garnett reiterated during his postgame sitdown with the media the same thing he did after a practice on March 20: He has a newfound respect for the back, and for back injuries.