Citing concerns that it would strain the data network, AT&T may have compelled Apple to deny approval for an application called SlingPlayer that would allow users to view television on their iPhone, according gadgets blog Electronista.

The report credits “a source close to Apple’s approval process,” but does not contain any comments on the record. So for now, it remains a rumor.

AT&T has meddled in the App Store before, pressuring Apple to remove the tethering app Netshare because it violated the AT&T’s terms of service.

Though, SlingPlayer is a unique case. The application is available on various AT&T BlackBerry devices and Windows Mobile Smartphones, so there are most likely no terms-of-service issues. It is also quite popular and made by Sling Media, the respected producers of Slingbox. Sling Media also promotes the iPhone version on its website, claiming, “We’ve been working hard to bring the SlingPlayer Mobile experience to the iPhone and iPod Touch. We’ve submitted the first release of our application to the iPhone App Store.”

Wired.com makes the point that the rumors may have a hint of truth, but the likelihood of the app being outright rejected is low. If anything, Sling Media might have to modify the application to work only via a Wi-Fi signal to keep it off the 3G.