Arizona Cardinals coach Bruce Arians has stated that he is not shocked by the poor form of quarterbacks such as Colin Kaepernick and Robert Griffin III.

The duo - who both excelled in the NFL last season - are struggling for their best football this time around, with Arians saying that the read-option offense is more suited to the college game as opposed to the national version.

Arians favours a traditional drop-back quarterback approach, which involves a lot of vertical passing, and he has led his team to second spot in the NFC West with a 7-4 record so far.

He told the Philadelphia Inquirer: "I still think the read-option is a great offensive method. It's a great college offense when you put a solid athlete back there.

"But when you're facing up against great athletes, with the speed that's in the NFL who are chasing these guys, unless you're superhuman, you're going to get hurt sooner or later - not hurt, but beat up and bruised up, and you don't want your quarterback feeling bruised up when he's trying to throw and be accurate."

Arians's side take on the Philadelphia Eagles on Sunday.