The phrase "to support the striker" means to help and assist the main offensive player in a sports team, usually by providing them with passes, creating scoring opportunities or drawing away defenders. Full definition
The Ox desperately needs confidence and e may feel a bit happier against lower League opposition and he may be played as support striker. (justarsenal.com)
If you want to use Sanchez as striker he should be playing supporting striker in a 4 -4-2 like with De Natale at Udinese. (justarsenal.com)
Ozil in support striker role like Bergkamp. (justarsenal.com)