Sweden's Stefan Olsson and The Netherlands' Diede de Groot will each seek successful title defences when wheelchair tennis singles competitions begin at Wimbledon tomorrow.
The event will mark the third Grand Slam of the International Tennis Federation Wheelchair Tennis season.
Sweden's Olsson secured the first singles Grand Slam title of his career in 2017 when he beat Gustavo Fernández of Argentina in a three-set final.
He has earmarked the grass courts as his best opportunity to win another.
"I think it could be possible [to defend the title] but it will be difficult with all the good rivals," he said.
"The grass court season suits me really well. In fact,
"I loved it from the very first time I played on it."
Japan's world number one Shingo Kunieda will be another leading contender.
De Groot, meanwhile, has already triumphed at the Australian Open since she beat Germany's Sabine Ellerbrock last year.
Japan's Yui Kamiji will also be a strong challenger.
Competition will take place over four days and culminate with finals on Sunday (July 15).
There are no quads singles event scheduled, but a quad doubles exhibition is due to take place for the first time.