Elina Svitolina is taking a much-needed break from tennis due to physical and mental stress brought on by injuries and Russia's invasion of her native Ukraine. 

The world number 20 revealed she had been struggling with a back injury that affected her preparations for tournaments, falling at the first hurdle in each of her past two events.

Svitolina, the 2018 WTA Finals champion, reached the last eight at the Monterrey Open, where she refused to play Anastasia Potapova unless the Russian was classed as a neutral athlete at the start of the month, but she lost in her first match at both Indian Wells and the Miami Open.

Svitolina's sabbatical means she will be absent from Ukraine's Fed Cup clash with the United States next month, and it remains to be seen if she will return in time for the French Open at the end of May.

The 27-year-old posted on Twitter: "It's been an extremely difficult couple of months for me not only mentally, but physically. 

"For quite a long time, I've been struggling with my back; the pain didn't let me prepare for the tournaments at my best.

"Meanwhile, observing with unbearable pain in my heart what is happening in my homeland of Ukraine and with how much bravery and courage our Ukrainian people are defending our country, this gave me a huge push to continue and fight on court.

"Now, my body can't handle it anymore and I need to rest, therefore I'm sad to announce that I will be missing the Fed Cup and a few of my favourite tournaments in Europe. But, I'm sure I will see you around soon, thank you for all your support in this challenging period."