Jannik Sinner put his chances of reaching the season-ending ATP Finals in Turin in major doubt by announcing he has withdrawn from home event the Florence Open.
The Italian had to retire from his semi-final against Holger Rune on Saturday and subsequently withdrew from this weeks Astana Open with the same injury.
Now the 21-year-old has revealed he won't be appearing at next weeks indoor event in Florence as he plans to let the injury heal.
He told Instagram: "Frustrating to have had to retire from my match in Sofia. I’ve spoken with my doctor and been advised that I need to take a short period of time off for the ankle to recover.
"Unfortunately that means I’ll miss next weeks tournament in Florence.
"Missing a tournament in Italy is extra painful for me."
The withdrawal from the hard court at the Palazzo Wanny arena will hurt Sinner all the more as it is the first time the event has been staged there since 1994 with the player set to reach the event as the number one seed.
Felix Auger-Aliassime now takes the top spot with Italians Matteo Berrettini and Lorenzo Musetti in second and third spot respectively.
Fresh from his astonishing win over Carlos Alcaraz in Astana, David Goffin will compete in Italy hoping to build on being the first man to defeat the new World No.1 in straight sets this year.
Sinner currently sits in 12th in the Race to Turin on 2310 ranking points and is running out of time to get some much needed wins under his belt.
However, the young San Candido man still has the Paris Masters to aim for with 1000 rankings point on offer to the winner.