Refusing to settle and pushing manufacturers to conform to its rigid specs, Apple may have to delay or downgrade shipments of its iPhone 6 as suppliers struggle to get production back on course after a screen revision consumed June and July.

Apple called for a rework of one of the iPhone 6's key components roughly a month before the press event where the tech company is projected to launch its latest smartphone, anonymous sources from Apple suppliers told Reuters.

The iPhone 6's backlight wasn't conveying enough luminance, so Apple called for a revision of the light source and brought the installation of the smartphones' screens to a temporary halt, according to the anonymous sources. The issue consumed supplier time and flexibility this June and July.

Apple was seeking to further flatten the iPhone 6 by stepping down from two layers of backlight film to a single sheet, which sparked a chain reaction that prompted supplier doubt on their ability to deliver the requested amount of screens in time for the launch of the iPhone 6.

Apple is expected to launch the 4.7-inch version of the iPhone 6 at its Sept. 9 press event and it is projected to release the 5.5-inch variant of the smartphone some time later. The 5.5-inch version of the smartphone is expected to launch in time to soak in at least some of the revenue from the 2014 holiday season.

An earlier report suggested that the 4.7-inch version of the iPhone 6 could experience supply limitations as Apple tries to fit the devices with screens composed of sapphire crystal and glass. The report indicated that the Apple and its supplier wouldn't be able to procure the required amount of sapphire in time for a Sept. 9 launch of the 4.7-inch version of the iPhone 6, and now a more recent report suggests that the tech company may have run out of time.

Apple filed an application with the U.S. Department of Commerce requesting permission to build onto its sapphire production facilities in its newly commissioned factory in Mesa, Ariz. The document was posted to Scribd by Matt Margolis, a senior analyst at PTT Research.

Apple requested priority approval of the application so that it could expand its operations by late August, but It appears the application hasn't been processed. The application references sapphire jewelry, which suggests Apple may have been seeking produce a larger amount of the crystal for the iWatch instead of the iPhone.