Mat Coch writes:

Looking sprightly as he strolled from the hospitality suite, driving overalls hanging loosely from his waist in the late, hot afternoon sun, few would have believed that just two days earlier Sakon Yamamoto had been struck down with food poisoning.

The Japanese driver was a late withdrawal from this weekend's Singapore Grand Prix after it was announced on Friday morning that he was unwell. Taking his place would be Christian Klien, who was already scheduled to drive the car in the opening practice session.

Team officials told Pitpass that Yamamoto 'ate something wrong' on Thursday night, and had stayed at the hotel throughout Friday feeling unwell. However, he returned to the track on Saturday and was spotted in the garages during qualifying, apparently feeling much better.

In fact the Japanese driver was feeling so well the team put him to work, forcing him to don his race suit in the sweltering mid-afternoon sun for a photo shoot in pit lane.

The 28-year-old's presence on Saturday sparked a wave of speculation, the latest in a string of unusual occurrences at the struggling team which has been forced to fend off concerns over funding and even suggestions of a takeover bid from Jacques Villeneuve.

Cynics within the paddock have suggested that Yamamoto's illness may have actually been more related to HRT's bank account - according to some the state of which is enough to make anyone feel unwell - than anything he may have eaten. The Japanese driver is believed to have contributed around $5million to the team to cement his seat, though allegedly the money has not been forthcoming.

This rumour was given some merit when Christian Klien's sponsor Upsynth was added to the HRT cars airboxes on Saturday, a move which seemed strangely coincidental considering team members were seen peeling another sponsor's branding off the team's media wall on Thursday morning.