With three quarterbacks ahead of him on the New York Jets' depth chart, Christian Hackenberg is overhauling his throwing motion.

A second-round pick in 2016, Hackenberg hasn't thrown an official NFL pass. Sam Darnold, Josh McCown and Teddy Bridgewater are all ahead of him in New York.

Hackenberg has been working with quarterback guru Jeff Christensen to rebuild his mechanics this offseason.

Christensen says Hackenberg has had to "start from scratch" on his throwing motion.