Apple (NASDAQ:AAPL) may increase the screen size of its iPhone 5S, the next version of the company’s flagship smartphone, to 4.3 inches from the current 4 inches, a move, which can delay the release date of the device until the end of this year, a new report said.

Apple, which is the world's leading smartphone manufacturer, was previously expected to release the iPhone 5S in September or October. However, incorporating a bigger screen, which will require a redesign of the product, could force the company to delay the release date of the new handset toward the year-end, Bloomberg reported on Wednesday, citing Commercial Times, a Taiwanese news publication.

The report also said that the iPhone 5S will be powered by a new processor, manufactured by Taiwan Semiconductor Manufacturing Co. (NYSE:TSM), which would likely deliver the chips for the handset only in August -- another potential factor for a delay in the iPhone 5S launch.

The Commercial Times report came hot on the heels of a report from DigiTimes on Tuesday, saying that yield issues with fingerprint-recognition chips and LCD driver ICs would likely delay initial supply of the iPhone 5S units.

However, the question is: Can Apple afford to make a last-minute change to the design of its flagship handset, which will lead the company away from its traditional holiday-season product release? And, here are the reasons why not:

Releasing the iPhone 5S later than the usual time-frame could result in Apple missing out on the money-spinning holiday season. And, given the fact that Apple is already battling sliding profits, the company is not likely to take further risks by not offering a new version of its popular handset, which has been a huge contributor to its success over the years, at the beginning of the crucial holiday season.

Also, according to a report from iDownloadBlog, increasing the iPhone’s screen size will certainly require Apple to re-design the handset based on a larger form-factor.

As the company is highly rumored to introduce multiple iPhone models soon, the Commercial Times report is not necessarily talking about the iPhone 5S, but probably a different iPhone altogether. Besides the iPhone 5S and a less expensive iPhone, rumors also suggest that Apple is working on bigger versions of the handset, with screen sizes ranging from 4.3 inches to 5.7 inches. The bigger iPhone model, dubbed the “iPhone 6,” is rumored to be released in 2014.

Apple introduced the 4-inch screen only with the launch of the iPhone 5 last year. Having said that, the company should be able to get away with another “S” model this year, carrying a similar design as that of the iPhone 5, but only with minor improvements to its internal specifications.