(Reuters) - World number three Carlos Alcaraz is unlikely to be at his best for Wednesday's ATP Finals match against Andrey Rublev as the four-times Grand Slam champion continues to struggle with illness, the Spaniard's coach Juan Carlos Ferrero said.

World No. 3 Carlos Alcaraz canceled his practice short on Tuesday due to ongoing illness and his coach offered an explanation.

Carlos Alcaraz struggled with a stomach issue and looked far from the player who won two Grand Slams this year in losing to Casper Ruud 6-1, 7-5 at the ATP F