Julien Alaphilippe's return from a long injury layoff was stopped by COVID-19.

Three months after his big crash in Liège-Bastogne-Liège, the world champion, who returned to competition at the Tour de Wallonie over the weekend, tested positive for a virus on Monday morning.

As a result, he did not start the third stage of the five-stage race in Belgium, making it highly unlikely that he will participate in Sunday's Clasica de Saint-Sebastien.

Alaphilippe suffered a broken shoulder blade, two broken ribs, and a punctured lung in a horrific crash in Liège. Alaphilippe took nearly a month off his bike to prepare for the Tour de France, but was not selected for Quick-Step Alphavinil.

Alaphilippe had been competing in the French national championships at the end of June for the Tour, but when that was not forthcoming, he reorganized his plans for the second half of the season.

He returned for Saturday's Tour de Wallonie, winning the opening stage of Mulle de Huy, the stage of his four wins in La Flèche Wallonne. In the second stage, he finished nearly 9 minutes behind the lead group, handing the leader's jersey to Rob Stannard (Alpecin-Desseuninck).

Alaphilippe will come out of the race on Monday morning and will likely miss the prestigious one-day classic in San Sebastián, which he won in 2018. If the rest of his program is unencumbered, he will compete in the Tour de Ain, which starts on August 9, before the Vuelta a España, which starts 10 days later.

Alaphilippe will then head to Australia for the World Championships, where he will try to win the road race rainbow jersey for the third consecutive year.

"The main objective this week is to have fun and get into the rhythm of the race," Alaphilippe said before the Tour de Wallonie.

"Of course I want to attack and get a result. But first I need to see where I am. It's good to go for the result, but it's also important to be in good condition."

"This year's program is different from previous years, and I want to stay fresh towards the end of the season. I've been training at altitude. I haven't done any crazy training to be ready right away, but I'm still interested to see what happens in Wallonie before San Sebastian. We have the Tour de Ain, so that will be a good block before the Vuelta.