The Launceston rider began 2014 in blistering form and with high hopes of playing a leading role in Europe's top races but was repeatedly struck down by sickness including a bout of pneumonia when sitting second in the Tour de France.

Despite the disappointment just a week out from the road world championships, the 29-year-old remains confident of returning to the form which should have seen him leading Team Sky into this year's Giro d'Italia.

"For me it's the end of the year now, and hopefully I can have a better season in 2015," he said.

"I'm not going to beat myself up too much, I had a year like this three seasons ago, and I've had some good ones since.

"I'm pretty happy to draw a line through the year and move on."

Having helped teammates to the last two Tour de France titles, Porte began this season in eye-catching form, winning a stage of the Tour Down Under and landing a podium in a top-class national road title.

He flew to his European base of Monaco with the expectation of defending his Paris-Nice crown, challenging for the Giro and supporting Chris Froome's Tour de France title defence.

However, little went to plan as illness forced Porte to abandon more races than he completed, failing to finish six of the 11 he entered.

Denied shots at Paris-Nice and the Giro, he stepped up to become Sky's team leader when Froome crashed out of the Tour, but could not sustain his push when the race hit the Vosges mountains — normally his bread and butter terrain.

He said yesterday that he had been struggling to overcome an illness that had plagued him all year, citing a "string of chest infections".

Deciding to pull the curtain down on his season, Porte informed national selector Bradley McGee that he would not be able to ride in this weekend's world championships in Ponferrada, Sunday.

"I haven't had the best of health this year. I spent the last week in Manchester speaking with the doctors and we've found that during the Tour I had a mild case of pneumonia."

He reported good health at a team training camp in Tenerife in June, which led to solid showings at the Criterium du Dauphine and throughout the opening week of the Tour de France.

Meanwhile, the likelihood of Launceston's other ProTour rider Matt Goss dropping down to the ProContinental ranks was all but confirmed yesterday with an announcement from South African-based team MTN-Qhubeka.

Interim general manager Brian Smith confirmed the nationality of his two latest signings as being British and Australian, the latter widely believed to be Goss who has already said he will be leaving ORICA-GreenEdge next year.

"They gave me four countries that they wanted a name from," Smith told Cyclingnews. "Theo Bos covers the Benelux area. I've got a rider from Australia to cover the Australian side of things, Tyler Farrar covers America and I've got an English guy to cover that side of things."

The team has already landed a major coup with the signing of Norwegian Edvald Boasson Hagen from Team Sky this week.

Porte's withdrawal and the omission of Ringarooma's Felicity Wardlaw leaves under-23s Alex Clements, of Launceston, and Hobart's Campbell Flakemore plus Devonport under-19 Macey Stewart as the Tasmanians at the world championships.

Elite men: Simon Clarke (VIC), Rohan Dennis (SA), Cadel Evans (VIC), Simon Gerrans (VIC), Adam Hansen (QLD), Heinrich Haussler (NSW), Matt Hayman (NSW), Michael Matthews (ACT), Rory Sutherland (ACT).

Elite women: Tiffany Cromwell (SA), Katrin Garfoot (QLD), Rachel Neylan (SA), Loren Rowney (QLD), Carlee Taylor (SA), Lizzie Williams (VIC).