Rafael Nadal will make his return to competitive tennis this week at the Italian Open, while Novak Djokovic participates in his first event since getting disqualified from the US Open.
Preparing for the rescheduled French Open, which begins on September 21, Nadal has won a record nine titles on the red clay of Rome, normally played in May but will start behind closed doors on Monday.
World No 1 Djokovic, a four-time Rome winner and five-time runner-up, lost to Nadal last year in the final.
The 33-year-old Serb is the top seed ahead of world No 2 Nadal, in the tuneup for the final Grand Slam of the season at the French Open which begins on September 27.
Djokovic won the French Open in 2016, with Nadal having won the last three titles since, taking his Roland Garros tally to 12.
Nadal, 34, has not played since winning the Mexico Open at the end of February, skipping the US Open over coronavirus concerns.
Djokovic tested positive for coronavirus in June after an exhibition tournament he organised, but won his 80th career title at the Cincinnati Masters - relocated to the New York bubble - last month. He also captured his 35th ATP Masters crown, matching Nadal's all-time record, with the pair battling to pull ahead in Rome this week.
Djokovic arrives in Rome after his bid for an 18th Grand Slam ended amid controversy at the US Open a week ago when he was disqualified after accidentally striking a female line judge with a ball during his last-16 match.
Nadal opens his Rome challenge on Wednesday against 27th-ranked fellow Spaniard Pablo Carreno Busta, the recipient of a first round bye, after his run to the US Open semi-finals.
Nadal could play either Greek third seed Stefanos Tsitsipas or seventh seeded Italian Fabio Fognini for a place in the final. The Spaniard has a 61-6 tournament record, having not lost before the quarter-finals since 2008.
Djokovic will start against either Italian Salvatore Caruso or a qualifier, with a potential semi-final clash against France's fifth seed Gael Monfils or tenth seeded Swiss Stan Wawrinka.
US Open finalists Dominic Thiem and Alexander Zverev, the 2017 winner, both pulled out after their runs in Flushing Meadows, with injured Roger Federer also sidelined.
Halep headlines women's event
Former French Open champion Simona Halep headlines the women's event which also includes defending champion Karolina Pliskova and two-time Rome winner Elina Svitolina.
Serena Williams withdrew due to a left Achilles tendon injury sustained in her US Open semi-final defeat.
The former world No 1, a four-time Rome champion, joined 2019 US Open winner Bianca Andreescu and two-time Wimbledon winner Petra Kvitova in skipping the Italian event which will also be without top-ranked Ashleigh Barty and newly-crowned US Open champion Naomi Osaka.
World No 2 Halep won the Prague title a month ago and the Dubai title prior to the shutdown, and will face either Anastasija Sevastova or Jasmine Paolini in the second round.
Former French Open champion Garbine Muguruza opens against American Sloane Stephens.
Venus Williams, the 1999 Rome champion, has a tough start against US Open finalist Victoria Azarenka, with the winner taking on third seeded Sofia Kenin.
Dutch player Kiki Bertens and Swiss Belinda Bencic are among the six top 10 players in the field.