Wagner, 44, is a 10-time champion at the International Tennis Federation’s season-ending championship for the world's top singles players on the UNIQLO Wheelchair Tennis Tour.

The world number one’s strongest challenger at the 25th edition of the prestigious tournament is expected to be Australia’s Dylan Alcott, who can count the NEC Masters crown as one of the few major titles missing from his list of honours in the quads division.

The Rio 2016 Paralympic gold medallist and four-time Australian Open champion has the chance to not only put that right this week, but also the opportunity to secure the year-end number one ranking.

Alcott arrives in Orlando ready to contest his first NEC Masters since finishing runner-up to Wagner in 2014.

He is currently 426 points adrift of Wagner in the standings.

Wagner faced a similar challenge for the top spot last year with Great Britain’s Andy Lapthorne having had the chance to finish 2017 as world number one if he had won the quads final.

Lapthorne and South Africa’s Lucas Sithole join Alcott and Wagner as former NEC Masters finalists among this year’s field of six players.

Completing the line-up is Japan’s Koji Sugeno, the world number four who is making his NEC Masters debut, and Australia’s Heath Davidson, who finished third on his debut in the event last year.

Three days of round-robin quads competition are due to begin tomorrow.

Also vying to retain a title is The Netherlands’ Diede de Groot in the women’s singles event.

A year on from winning her first NEC Masters title, the 21-year-old has an unassailable lead at the top of the world rankings.

Her defence is likely to be met with tough opposition, though, with world number two Yui Kamiji of Japan and world number three Aniek van Koot of The Netherlands both former champions. 

In 2013, the last time the NEC Masters was held in the US, Kamiji became the only non-Dutch player to win the NEC Masters women’s title - a distinction she retains to this day. 

If anyone is to prevent a second successive De Groot-Kamiji final it could well be 2014 NEC Masters champion Van Koot, the only other player to win a Super Series women’s title this season and the only player to have beaten both since January.

The men's singles entries include four former champions - current world number one and three-time champion Shingo Kunieda of Japan, France’s Stéphane Houdet and two-time champions Joachim Gérard of Belgium and Stefan Olsson of Sweden.

Kunieda earned the second of three successive NEC Masters crowns when the event was last held in US in 2013 in Mission Viejo and this season he has won two of the four Grand Slams and three of six Super Series titles.

In the absence of 2017 champion Alfie Hewett, Gordon Reid flies the flag for Britain this year as he seeks to improve on his runners-up finish at the last two NEC Masters.

The six players in the quad singles and the eight players in both the men’s and women’s singles all begin their respective events in two round-robin pools.

The top two players in each pool after the completion of the round-robin phase will go forward to the semi-finals.