The Bora-Hansgrohe rider had won two stages of the race so far, and was very much in the running for the green jersey. He won stage two into Utrecht, before stage three into Breda as well, his first Grand Tour stage wins since 2020.
Bora posted on Twitter: "[Bennett] returned a positive antigen test this morning, and also showed some symptoms. Therefore we decided that he wouldn’t start today’s stage."
Speaking to Cycling Weekly shortly after he finished his time trial effort, Bennett's teammate Ryan Mullen said that it was a "massive shame" for both himself and the team. especially as he had proved he was the "quickest guy" at this year's Vuelta.
"It still hurts to talk about," the Irishman said. "It's a really big shame for Sam and the team, and myself, because Sam is a great guy and he has come back to his best form. Unfortunately Covid has caught up to him, along with another few guys in the race.
"Clearly someone brought it in and now it's going around all the teams. It's a massive shame and Sam is really disappointed. He deserves to be here, he has put the work in, and he was showing he's back to his best. I'm sure he probably would have won the green jersey, and now Mads Pedersen is going to go to the end with it."
Bennett trailed Pedersen by just five points, and with just a couple of sprint stages still to come in the next fortnight, it was very much a two-horse race in the points classification.
He is the eighth rider to withdraw from the race between the end of Sunday's ninth stage and the start of the time trial, and the 12th man to leave the race following a positive Covid test.
Ethan Hayter (Ineos Grenadiers), José Herrada (Cofidis), Harry Sweeny and Jarrad Drizners (both Lotto Soudal), and Mathias Norsgaard (Movistar) all left the race following positive COVID-19 tests on Tuesday morning, while Edoardo Affini (Jumbo-Visma) and Floris De Tier (Alpecin-Deceuninck) are out with illness and saddle sores respectively.
Mullen said that Bennett has "proved he's back" at this Vuelta, and this is what makes it all the more galling.
"He's definitely back, he was the quickest guy in the race here by a mile," he said. "It's really disappointing for everyone and I'm gutted for Sam, he has put in all the work and all the prep to be here, he's in his best shape. He has proved he's back.
"The only real disappointment is that the workload from this race would have put him in really good stead for next year. He would have carried this momentum into next year, cos there are three more sprints he would probably be guaranteed to win."
As for when he returns to racing, Mullen said: "If I was Sam with the form he's got, I'd be racing wherever he could."
"It's going to come down to the medical department and the team to tell him when he can train again," he continued. "He's probably going to need a few days to recover and get the virus out of his system. Who knows, maybe he could actually start something like the Tour of Britain, if he's ready."
It is the latest cycling-related blow for Ireland on Tuesday, after it was revealed that the country would not be sending riders to the World Championships in Australia in September due to financial constraints.
Thank you for reading 20 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1