Carlos Alcaraz has been given a blunt reality check about his chances on the indoor hard courts.

The world No. 2 is preparing to return to action at next week’s Paris Masters before heading to Turin for the ATP Finals.

But Roger Federer’s former coach says Alcaraz hasn’t “convinced” him on the surface, claiming Alexander Zverev is above him.

Compared to his results at other tournaments, Alcaraz has often struggled during this part of the season. The Spaniard has never won a title on indoor hard court and, last year, he lost back-to-back opening matches at the Paris Masters and ATP Finals.

He still bounced back and reached the semi-final of the year-end championships but was thrashed by Novak Djokovic. The world No. 2 will now be hoping to prove himself on the surface and end his season on a high in Paris and Turin.

However, Federer’s ex-coach isn’t convinced. Ivan Ljubicic believes Jannik Sinner is the clear favourite to lift the ATP Finals trophy in his home country. And Alcaraz isn’t even his second pick, as he claimed Zverev was closer to the world No. 1.

“Yes, for me [Sinner] is the dark horse,” Ljubicic told Sky Sports. “Also because Alcaraz still has to convince me on the indoor court.”

Ljubicic, himself a former world No. 3, hasn’t been encouraged by what he saw from the four-time Major winner this time last year.

He continued: “He has a very high level on hard, but on the indoor court even in Turin last year he suffered a lot, especially from a mental point of view.

“Let's see if that changes this year. If we want to find someone who is closer to Jannik I would say Zverev.”

Alcaraz should have more confidence on the surface this time. The Spaniard played a crucial role in helping Team Europe win the Laver Cup on his debut at the tournament last month, also played in an indoor arena.

He also won both of his matches during Spain’s Davis Cup qualifier tie in September and enjoyed a successful Asian swing.

Alcaraz picked up the China Open title - his first-ever title that has come in the post-US Open part of the tennis season.

The 21-year-old will be the second seed in Paris and will learn his fate in the draw on Friday evening. Alcaraz’s best result at the tournament is a quarter-final run in 2023, when he was forced to retire from his match with an abdomen injury.