Spain's world number one Carlos Alcaraz has been forced to pull out of the upcoming ATP Finals and Davis Cup Finals due to injury.

A scan revealed an abdominal muscle tear, which he confirmed on Twitter would keep him out for up to six weeks.

"It is tough and painful for me to miss these two events," wrote Alcaraz.

"All I can do is be positive and focus on my recovery."

Alcaraz, who has shot up the rankings this season after winning five titles on the ATP Tour, including the US Open, was due to be number one seed on his debut at the season-ending event in Turin next week.

He was also due to play an important role in the Spain team at the Davis Cup Finals, which take place in Malaga at the end of the month.