Carlos Alcaraz says winning the Davis Cup for Rafael Nadal is a "huge motivation" and will mark the "most special" tournament of his career.
Nadal, a 22-time Grand Slam champion, will retire from tennis after representing Spain in next week's Davis Cup Finals in Malaga.
Spain face the Netherlands in the quarter-finals on Tuesday as they look to add to their six titles - four of which Nadal has played a part in.
"It's probably the most special tournament I'll play in my career, because of what's happening, because of the circumstances," said 21-year-old Alcaraz, who is ranked third in the world.