How do you view the 49ers-Cardinals rivalry?

Sunday afternoon, the governor of Arizona sent a congratulatory tweet to Arizona Cardinals wide receiver Larry Fitzgerald. Fitzgerald thanked her, and then said the Cardinals had a big matchup coming up against the Cardinals' biggest rival.

Thanks @GovBrewer one win at a time. We have a real big one coming up next week vs our biggest rivals the 49er's.

— Larry Fitzgerald (@LarryFitzgerald) September 14, 2014

The Cardinals and 49ers have been in the same division since 2002. During that time, San Francisco is 16-8 against Arizona, and has won nine of the last ten matchups. Some of the games have been close, some not so close. It is not a rivalry in the sense of what we see between the 49ers and Seahawks, but is it more than what the 49ers have with the Rams right now? Divisional opponents are always going to have at least some measure of rivalry with each other. They play each other twice a year, and with the limited wild card opportunities, a close divisional race can make for an exciting finish.

The Cardinals took a big step forward in 2013, improving from 5-11 to 10-6. They lost some key parts this offseason, due to free agency, injuries and a suspension. They have gotten off to a quick 2-0 start, and a win over the 49ers would probably go a long way toward validating them for the rest of the NFL. Some might think they are already legit, others are probably questioning their worth, so a win over San Francisco would quiet things for a bit.

The 49ers biggest current rival is Seattle, and their biggest historical rival is Dallas. You can mix in the Packers and Giants given some of the history. Where does Arizona fit in?