Rumours are increasing that Casey Stoner may miss this weekend's Czech Republic Grand Prix at Brno - and possibly the following Indianapolis and Misano rounds - in order to get a grip on the mysterious physical problems he has suffered at the last five rounds.
The 2007 world champion suffered sickness at round six in Catalunya, followed by fatigue at the following events, but extensive medical tests after round eight in Laguna Seca indicated only 'slight gastritis and mild anaemia', a diagnosis Stoner openly doubted.
Stoner then reported little improvement in his condition at Sachsenring and Donington, where a wet tyre gamble left him 14th in the race.
The Ducati Marlboro star, who hasn't won since round five, was due to undergo further medical tests during the summer break, which ends with this weekend's eleventh round of the season.
Stoner was leading the world championship at the start of the Catalunya event, but has now dropped to third in the MotoGP World Championship, 37 points behind leader Valentino Rossi after ten of 17 rounds.
A Ducati press release previewing this weekend's Brno round is expected today (Monday).
Should Stoner withdraw, Pramac Ducati's rookie star Mika Kallio is tipped to replace the Australian, alongside Nicky Hayden, at the Ducati Marlboro Team.