Djokovic had talked about possibly skipping the grass-court season following his quarter-final defeat to Marco Cecchinato at the French Open.

The 12-time grand slam champion is still not back to his best having been blighted by injury problems in recent times.

He is set to pit himself against a star-studded field in London, joining French Open champion Rafael Nadal, Grigor Dimitrov, Marin Cilic and Juan Martin del Potro in competing for the title.

Fellow former world number one Andy Murray is also on the entry list, but his participation remains in doubt with the three-time grand slam champion having not played in 2018 after hip surgery. 

The Briton, who has won Queen's a record five times, pulled out of this week's Rosmalen Grass Court Championships.

"I am very excited to be playing the Fever-Tree Championships again. I have happy memories of reaching the final at The Queen's Club 10 years ago and also winning the doubles title. The atmosphere is always great and I am looking forward to playing in front of the British crowd again.

"After the exciting events in Rome and Paris, I'm ready for new challenges. Grass is very special, it is the rarest of surfaces so I'm happy I'll have the opportunity to compete at this strong tournament, which will also be a great preparation for Wimbledon.

"Marian Vajda and Gebhard Phil-Gritsch will be with me in London, and this makes me happy."

Djokovic lost to Nadal in the 2008 final. He won the doubles competition at the event in 2010 alongside Jonathan Erlich.