Mark Cavendish made his first competitive appearance in a Team Sky jersey in the Tour of Qatar on Sunday.
The Manxman, who switched to the British-run team after winning the Tour de France's green jersey and the world championships last year, had fallen ill on the flight to Doha but was given the all-clear by team doctors.
Team Sky directeur sportif Steven de Jongh said: "Our medical team have done a fantastic job in looking after him and Mark has followed their advice to the letter.
"Clearly, he's not going to be at his best in the next few days but we're hoping he'll get stronger with every passing stage.
"We'll continue to keep a very close eye on him but hopefully he's over the worst of it now."
Unsurprisingly, Cavendish did not feature in the first stage, a 142.5 kilometres ride from Barzan Towers to the College of the North Atlantic, which was won by Belgian former world champion Tom Boonen.
The Omega Pharma-Quick Step rider took the line ahead of Adam Blythe (BMC Racing) and Peter Sagan (Liquigas-Cannondale) in third.
De Jongh added: "He (Cavendish) was helping out his team-mates during the race, which was a pleasant surprise because we'd told him he didn't have to do anything if he didn't feel he was up to it after his illness.
"Our only goal for him was that he finished the stage today, and he did that comfortably."
