Following the announcement of the Tour de France squad on Monday, Belgium's Quick-Step Alphavinir was forced to change its plans just three days after the race's start after key domestique Tim Declercq tested positive for COVID-19.

The Belgian, who was expected to play a key role in Quick-Step's eight-man lineup in France, had already arrived in Copenhagen after testing positive three days before the Grande Palais.

Quick Step Alphavinir called up Florian Seneschal as a substitute.

On Monday, the French champion was named one of two reserve riders, along with 2021 green jersey winner Mark Cavendish.

Neither rider fits De Clercq's profile in terms of pulling the peloton early in the stage and chasing the breakaway, but the classics specialist and fast finisher Senecal can join the lead-out train of chosen sprinter Fabio Jacobsen

Senecal was particularly disappointed to be left out of the original eight-man team after winning the French road race title on Sunday.

"I was hoping that being French champion would change the game, but even for the world champion it doesn't matter," he said, referring to fellow countryman Julien Alaphilippe, who was also left out of the squad.

"The team informed me that they wanted to choose a Dane to give a good image to the Grande Pearl in Copenhagen. 'Marketing is also important. The Tour de France is a big advertisement."

De Clercq's positive test represents another setback in what has been an unforgettable year for the 33-year-old, his second positive test of the season after February's Tour of Saudi Arabia.

He then contracted pericarditis, forcing him to miss the opening weekend and most of the spring classics. He returned to racing at the Tour de Hongri, Tour de Suisse, and the Belgian national championship road race, but will miss the Tour, his major goal this summer.