Sources close to Sinner told BBC Sport that he feels Ferrara, who has been working with Matteo Berrettini, has learned from his mistakes.

Ferrara has a degree in pharmaceutical technology and was specifically chosen by Sinner previously to advise him on anti-doping issues.

The initial independent tribunal found Ferrara provided the spray to Naldi with a warning – but in the knowledge it contained a prohibited substance and the physio would be treating Sinner with his bare hands.

As part of his defence – outlined in the tribunal’s decision last August – Sinner’s legal team argued that it was “not the gravity of Mr Ferrara’s mistake that the player is responsible for but his choice in appointing Mr Ferrara in the first place and his supervision of him”.

In reaching a settlement with Sinner, Wada said Sinner tested positive as a result of the “negligence of members of his entourage” and, under its code, this is a negligence an athlete bears responsibility for.

BBC Sport has asked Sinner’s representatives whether Ferrara will once again have responsibility for anti-doping matters.

But Sinner believes he can trust Ferrara again and – importantly for a player chasing the biggest prizes – feels the reintroduction of a familiar face is essential to maintaining his place at the top of the game.