Last year’s winner, Portugal’s Pedro Sousa, has already been given a wild card to the tournament, the country’s only ATP 250 competition, which runs from 27 April to 5 May. A total of three wild cards are permitted.
Other players taking part in the men’s competition this year include South Africa’s Kevin Anderson, Greece’s Stefanos Tsitsipas, France’s Gael Monfils and Italy’s Fábio Fgnini.
"Playing in the Estoril Open is always a pleasure and I have always felt cherished by both organisers and the public,” a statement from organisers quoted Busta as saying. “It's been a very important tournament in my career. It was in Portugal that I got my first ATP title on clay and always got good results."
He thanked organisers for "the opportunity to play after having been injured for more than two months."
The tournament director, João Zilhão, pointed out that Busta is the most successful male player to win the Estoril Open in its relatively short history.