Both are men who have plenty of NFL experience. McDonald played safety for 12 seasons in the NFL with the Arizona Cardinals and San Francisco 49ers. He won a Super Bowl while being named an All-Pro six times and going to as many pro bowls.
As for April, he doesn't have near that amount of time in the league but he has coached before. April had spent the past two seasons as a quality control coach for the Philadelphia Eagles, but is moving on after Andy Reid was fired.
These are just more changes in an organization that is going to need nametags soon. Rex Ryan was kept despite a miserable 6-10 campaign, but nine other coaches have either been left or let go including both coordinators, Tony Sparano and Mike Pettine.