World number one Carlos Alcaraz said on Tuesday he has pulled out of the Davis Cup Finals in Bologna due to a swollen hamstring, adding he was "heartbroken" to miss out.

The Spaniard aggravated the problem during the ATP Finals, where he was beaten by Jannik Sinner in Sunday's title clash.

"I'm so sorry to announce that I won't be able to play for Spain in the Davis Cup in Bologna," Alcaraz said on Instagram.

"I have edema in my right hamstring and the medical recommendation is not to compete.

"I've always said that playing for Spain is the greatest thing there is, and I was really looking forward to helping us fight for the Davis Cup. I'm going home heartbroken."

Spain are due to face the Czech Republic on Thursday in the quarter-finals of the Davis Cup Finals, which are scheduled to conclude on Sunday with the title clash.