[Editors’ note: This article was updated March 17 with additional news of player signings.] With the arrival of a new league year on March 17, free agent deals can become official and already three quarterbacks — including the first and second picks in the 2016 draft — have been traded. More movement, possibly much more, will follow. Frustrated stars, well-priced veterans, young starters — all could be on the move, as this emerging era of quarterback empowerment collides with a salary-cap crunch that compels teams to assess their resources at the sport's most critical position. Here’s a partial list of quarterbacks who will be — or might be — wearing new uniforms when the 2021 season opens next fall.