Five-time Queen's Club Championships winner Andy Murray will compete for the 2021 title ahead of a possible Wimbledon return.
In-form second seed Stefanos Tsitsipas stands in the way of Rafael Nadal and a 12th Barcelona Open title
Normal service was resumed for Rafael Nadal after Kei Nishikori took the second set off the top seed in Barcelona.
Rafael Nadal toiled in Barcelona but Novak Djokovic was in fine form at the Serbia Open on Wednesday.
Jannik Sinner has won his previous two matches against Roberto Bautista Agut, and now he will target a third success, on clay in Barcelona.
Japanese star Kei Nishikori emerged from the jaws of defeat to progress at the Barcelona Open on Monday.
Alexander Zverev topped Stefanos Tsitsipas to reign supreme at the ATP 500 tournament on Saturday.
Aslan Karatsev was a stranger to the world's top 100 before this season, but he has reached a grand slam semi-final and won a title in 2021.
Stefanos Tsitsipas defeated teenager Lorenzo Musetti in less than 80 minutes in the Mexican Open semi-finals.
Alexander Zverev reached the Mexican Open final, but not before an earthquake struck during his semi.