One obvious link is that Harden played his collegiate ball at Arizona State, but perhaps not as commonly known is that Harden's mom still lives in Arizona. Harden has a home in the area as well.
Suns fans probably took notice when the Thunder extended Serge Ibaka by four years after already having Kevin Durant, Russell Westbrook and Kendrick Perkins under contract long term. Harden, the reigning Sixth Man of the Year, could be the odd man out in OKC, although Mike Prada of SB Nation thinks Ibaka's signing will have the opposite effect on his status with the team.
As Bolvin points out, it'll likely come down to whether Harden will want a max deal --- which Phoenix could potentially offer --- or wants to stick around with a budding powerhouse in Oklahoma City.
For the latest on the Oklahoma City Thunder, be sure to check out Welcome to Loud City.