Roberts to miss Assen - Kagayama gets call-up.

Team Suzuki rider Kenny Roberts Jr has been ruled out of next weekend's Dutch TT at Assen, after doctors in the USA diagnosed more extensive internal injuries than first suspected.

Roberts, who won the 500cc World Championship in 2000, sustained the injuries when he collided with team-mate John Hopkins in the early stages of the Italian GP, on June 8.

His hopes of being fit for the Catalan GP, the following weekend, were dashed by worsening chest pains, and he flew home to California for medical treatment on the eve of that race.

"It feels like I just crashed yesterday," he said.

Roberts consulted famed surgeon Arthur Ting, and underwent a scan that revealed deep soft tissue damage to his chest and upper abdomen. He was ruled out of the Dutch TT, and although doctors suggested a further six weeks recuperation were necessary, he hopes to be fit for the following round, the British GP at Donington Park on July 13.

Kenny's place on the 990cc GSV-R prototype at the Dutch TT will be taken by Japanese rider Yukio Kagayama. 'Yuki' currently races for the Rizla Suzuki British Superbike team, and mixed with the WSBK stars as a wild-card last weekend at Silverstone.

Kagayama will go directly to the Netherlands from Brands Hatch, where he is contesting a BSB race this weekend.

A Suzuki rider since 1993, Kagayama already has GP experience on the 500cc two-stroke, with a best of sixth place in the Malaysian GP in 1998. Last year, he helped develop the first version of the GSV-R in Japan, winning three All-Japan Superbike races in the process.

"I hoped to race in at least one GP this year. The chance has come earlier than I thought - and I am really looking forward to it," he said.

"We've worked with Yukio before, and we know that he not only tries really hard, but brings a positive attitude as well," declared Team Manager Garry Taylor. "We join a lot of other people in admiring his hard-charging performance in the recent World Superbike round in Britain.

"Of course it's a blow to lose Kenny at a crucial time of urgent machine development," confessed the Brit. "Luckily John Hopkins appears to be just about over his injuries from Mugello, and he not only raced in Catalunya but put in a day's testing after the race as well. We know he will put in his usual 100 percent, while Yukio's input will be another welcome source of data for the race engineers."