The Arizona Cardinals have sold out every home game since they opened University of Phoenix Stadium in 2006.

But it hasn’t always been easy.

It used to be difficult for the team to sell tickets to games vs. NFC West foes but now the team is using games against the San Francisco 49ers and Seattle Seahawks to boost sales to other games. According to Kent Somers of the Arizona Republic, the team’s “Protect the Nest” ticket plans are now directly tied to the 49ers and Seahawks.

To get a ticket to the 49ers game on Dec. 29, fans must also buy one to the Panthers game on Oct. 6. To get a ticket to the Seahawks game on Oct. 17, fans must also buy one to the Aug. 17 preseason game vs. the Cowboys.

In previous years, Protect the Nest plans forced fans to buy tickets to a total of three games. The Seattle game was a concern for the team just last season so it tied tickets to the Bears game with the Seahawks game to boost sales.

Now, the NFC West looks like the toughest division in football and the Cardinals hope that helps them at the ticket window. The packages go on sale to the general public beginning Friday.

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Brad Biggs covers the Bears for the Chicago Tribune