Christian Hackenberg is 25 games into his NFL career, but he has yet to play a snap. The Jets’ second-year quarterback is third on the depth chart. With Josh McCown playing well, Hackenberg could go his first two years in the league without playing at all. But don’t tell the man who drafted the former Penn State quarterback with the 51st pick in 2016 that Hackenberg’s sluggish development is discouraging. “I think the one thing with any player is they all develop at different paces and different rates,” general manager Mike Maccagnan said Wednesday at his midseason address to the media. “I think [the preseason] was good experience for Christian. I think we got an idea of areas where he still needs to improve upon, like every young player. I wouldn’t necessarily say [I’m] discouraged.” How could he not be? Maccagnan took Hackenberg in the second round, a premium pick where you expect some impact from the player in his first two seasons. Instead, Hackenberg has been active for just two games — both when Bryce Petty was injured. The Jets gave Hackenberg every opportunity this summer to win the starting job, but he stumbled. He finished the preseason 32-of-74 (56.8 percent) for 372 yards with two touchdowns and two interceptions. He had a quarterback rating of just 68.1 and led the Jets to points on five of his 36 drives.