Real Madrid midfielder Lucas Silva has denied he is to retire from football after a heart problem was discovered during medical examinations ahead of a collapsed loan switch to Sporting Lisbon.

Silva had been due to join Sporting on a season-long loan, but the move fell through following the discovery of abnormal heart rhythm in his tests with the Portuguese club.

Reports Silva had retired emerged after the Brazilian edited his Instagram bio, which reads: "I fought the good fight, I've finished my career, I've kept my faith."

However, Silva - who spent last season on loan at Marseille - has emphatically denied that speculation in a post on Twitter.

The 23-year-old labelled the reports "untruthful", writing: "On Friday, when performing medical exams to sign with Sporting Clube de Portugal, [I] did a stress test, which detected a change in heart rhythm.

"Then and even today I did various examinations that did not find any abnormality in my heart. Apparently it was a single alteration and without specific cause.

"For safety it was decided it would be better to not transfer me right now.

"Obviously Real Madrid may want to repeat the tests, but I'm very sure of the absolute normality of the additional tests.

"In the face of untruthful news conveyed in the media, [I] decided to report, officially and categorically, I will not retire."