During the second quarter of a week 2 contest against the Dallas Cowboys on September 20 , 2015 , Alonso suffered a Grade II sprain – a partial tear – of his repaired left anterior cruciate ligament ( ACL ) .
In a Week 2 game against the Dallas Cowboys on September 20 , 2015 , Kiko Alonso had a Grade II sprain of his left ACL during the second quarter .