Adam Peaty will not take part in the mixed 4x100m medley relay heats on Friday morning, as Team GB begin the defence of their Olympic title.

Peaty, 29, tested positive for Covid-19 on Monday – a day after winning Olympic silver in the 100m breaststroke.

Missing the heats does not mean Peaty could not come in for the final on Saturday evening, should Team GB qualify.

He could also compete in the men’s 4x100m medley relay which begins on Saturday, if fit enough and the coaches wish to utilise him in that race.

Peaty did not swim in the heats as Britain took bronze at the World Championships in the mixed event earlier this year before coming in for the final, but he did when the Britain won the Olympic title three years ago in Tokyo.

He has been in the pool in recent days during training sessions, raising hope that he will be fit to compete.

James Wilby, who was 11th-fastest in the 100m breaststroke semi-finals and missed out on the final, will take on the breaststroke leg in Peaty’s absence with Kathleen Dawson, Joe Litchfield and Anna Hopkin making up the quartet.

The heats begin at 11:03 BST, with Team GB in the second heat. The eight teams with the best times across the two heats will qualify for the final.

One of the British squad’s best freestylers, Matt Richards, Tom Dean, Duncan Scott or James Guy, who won gold in the men’s 4x200m freestyle relay, could also come in if they qualify for the final.