Cardinals' coach Ken Whisenhunt and Chiefs coach Todd Haley are close friends and colleagues.
While Sunday's game will be the first time they've faced each other as head coaches, in some ways it's just a continuation of their relationship.
Since developing a friendship while assistants with the Jets, Whisenhunt and Haley competed at nearly everything. They often played basketball at lunch time, and sometimes the games became so heated that one of them would end up walking back to work instead of riding in the other's car.
But Haley was one of Whisenhunt's first hires when he got the Cardinals job in 2007, and his willingness to turn a good portion of the offense over to Haley is a big reason Haley got a head coaching job after Super Bowl XLIII.
Haley called plays that year and helped design much of the offense around quarterback Kurt Warner. He and Warner also butted heads at times, but were close friends, often swapping texts at all hours whenever ideas popped into their heads.
Both the Chiefs and Cardinals enter this game badly in need of a victory.
The Cardinals have lost four straight and fallen from contention into last place in the NFC West.
The Chiefs (5-4) have lost two straight and are now tied with the Raiders for the AFC West lead.
A victory would give the Cardinals a huge boost before they return home to play three consecutive games, including two within the division.
The Cardinals seem to be settling in on offense behind quarterback Derek Anderson.
It's not a group that's going to produce tons of yards and points, but it's shown in recent weeks that it can be competent.
As long as the defense holds up, and the kicking game continues to produce big plays, that will be enough to keep the club in contention for a third consecutive division title.