Roger Federer was handed a potentially tricky draw at the Madrid Open. Rafael Nadal, meanwhile, eyes a return to form.
Federer is into the semifinals in Istanbul, an ATP 250 event played on clay courts that he is expected to win.
Madrid shapes as a much bigger test in what is the second-last Masters event before the French Open later in May.
Federer, the top seed, gets a first-round bye before a potential meeting with Australian Nick Kyrgios. The Aussie is in his second tournament back from an ankle injury and has surged into the last four in Estoril. The enigmatic 20-year-old is a regular threat to the biggest names, with his serve and forehand capable of doing plenty of damage.
All eyes will otherwise be on four-time winner Nadal, who has clinched the Madrid title the past two years. The Spaniard has suffered losses to Novak Djokovic and Fabio Fognini in his past two clay-court tournaments. Despite his recent struggles, Nadal should negotiate his way through the early rounds — with either Steve Johnson or a qualifier awaiting him after his first-round bye.
Andy Murray is enjoying a deep run in Munich before he takes his spot as the second seed in Madrid. The Brit is yet to win a clay-court title, but that may change before he arrives in Spain. Murray will meet either German Philipp Kohlschreiber or a qualifier in the second round in Madrid.
Japan's Kei Nishikori was runner-up last year and comes into Madrid having claimed the title in Barcelona.
Canadian Milos Raonic, Czech Tomas Berdych, Spaniard David Ferrer and Switzerland's Stan Wawrinka are the other top eight seeds.
Berdych could potentially face Richard Gasquet in the second round, while Ferrer may meet Tommy Robredo and Wawrinka could take on Jerzy Janowicz.
Wawrinka has battled since winning the title in Rotterdam in February, needing a run of victories to get his season going again.