Adam Peaty was left out of the mixed 4×100 metres medley relay heats but he could still appear in Saturday’s final.

Peaty, part of the line-up that helped Team GB win the inaugural event at Tokyo 2020, tested positive for Covid on Monday morning, hours after winning silver in the men’s 100m breaststroke final on Sunday.

While he posted a photograph of himself back in the pool on his Instagram stories on Wednesday after two days of “bed rest”, Peaty was conspicuously absent as Team GB qualified fifth fastest for the showpiece.

His place went to Commonwealth Games gold medallist James Wilby, who might now drop out to accommodate Peaty on Saturday as Team GB are able to alter their line-up, as is the case in all relay races.

When asked when he discovered he would be racing in Peaty’s place in the preliminaries, Wilby told the PA news agency: “We always have rough draft ideas but confirmation for me came through two days ago.

“It’s a case of piecing together a relay team in the morning that will put us in a really good position. I think the decision for the final will be made pretty shortly and that will be about how we can make a better result in the final.

“Truthfully, I want the fastest breaststroke swimmer to be in that race in the breaststroke leg. That is something I’d love to be a part of but it depends on the health of other athletes.

“I’m not here to discuss what that may or may not be but depending on what that is, that will decide whether I’m part of that team or not.”

Kathleen Dawson, Joe Litchfield and Anna Hopkin made up the rest of the quartet but it is likely Team GB will make changes and much could depend on the availability of Peaty.

His hopes are boosted by there being no specific coronavirus restrictions on athletes, unlike in Tokyo, but Team GB said in a statement “all usual precautions (were) being taken to keep the wider delegation healthy”.

Wilby added of Peaty: “We’ve got a fantastic procedure in place. I haven’t seen too much of him as a result of that but that’s a good thing, he’ll be resting up as best as he can.

“I’m sure he’s wanting to put his best race in and if he’s in a position to do that, he’ll be doing that, for sure.”

Peaty – who may also compete in the men’s 4x100m medley relay, starting on Saturday – claimed gold in Tokyo alongside Dawson, Hopkin and James Guy.

Litchfield may also drop out in favour of Guy or another freestyle swimmer in Duncan Scott, Matt Richards or Tom Dean.

Wilby added: “We’ll be challenging in the final and it would be nice to get as close to replicating or replicating the result we had in Tokyo.”