British number one Emma Raducanu has withdrawn from the Madrid Open with a hand injury hours before her first-round match.

The 2021 US Open champion, hindered by a wrist problem in recent months, was set to face Bulgaria's Viktoriya Tomova on Wednesday.

Raducanu, 20, is now almost certain to drop out of the world's top 100.

Her withdrawal came a day after a terse news conference in which she used just 58 words to respond to 16 questions.

Raducanu's most recent appearance was a one-sided defeat by Jelena Ostapenko in Stuttgart this month, after which she dropped to 85 in the world rankings.

She skipped Great Britain's Billie Jean King Cup defeat by France the week before that to prepare for the clay-court part of the season.

Defeat in Stuttgart was her second in a row in the opening round, after losing to Bianca Andreescu in the Miami Open last month.

Raducanu suffered discomfort in her right wrist against Andreescu and later said she must find a long-term solution.

The injury ended her 2022 season early and returned before Indian Wells this month, when Raducanu reached the last 16 despite preparations also being hampered by tonsillitis.

Raducanu, who has played only nine matches this season and has also struggled with an ankle injury, is due to compete in the Italian Open in Rome starting on 8 May, before the French Open - the second Grand Slam of the year - begins on 28 May.

Analysis

BBC tennis correspondent Russell Fuller

Raducanu's biggest concern at the moment is her right wrist, which first caused problems at the end of last season.

Practice sessions have been especially compromised since March, and even though she was able to train here in Madrid, it appears the pain ultimately became too much.

Raducanu and her team were hoping the wrist could be managed, but there now seems an acceptance a long-term solution will have to be found.

What impact that will have on her participation at the French Open and Wimbledon remains to be seen.

Raducanu has said the pain of the injury comes and goes.

Its effect on her was perhaps illustrated by the terse exchange with two British reporters in Madrid on Tuesday.

She has lost her past three matches, all to Grand Slam champions. She was beaten by the world number one Iga Swiatek in Indian Wells, and then to Bianca Andreescu in Miami and most recently Ostapenko in Stuttgart.

Raducanu will very likely find herself outside the top 100 when the next rankings list is published on 8 May.

And even though she has very few of last year's points to defend until August, there is now a big question mark as to how often she will be able to play.

Once a player's ranking falls below 100, they are unlikely to receive direct entry into even Grand Slam tournaments.

Raducanu's status means she is likely to attract wildcards from tournament promoters, but the alternatives are qualifying for tournaments or dropping down to play on the ITF World Tennis Tour.