<p>Alexander Zverev said he suffered a "very serious injury" when he damaged his ankle and was forced to retire from his French Open semi-final against Rafael Nadal on Friday.</p>.<p>"It looks like a very serious injury but the medical team are still checking it and I will keep you updated," the German world number three said in a video message released by Roland Garros.</p>.<p>Nadal was 7-6 (10/8), 6-6 ahead when Zverev injured his right ankle and had to be taken off the court in a wheelchair before retiring from the match.</p>
<p>Alexander Zverev said he suffered a "very serious injury" when he damaged his ankle and was forced to retire from his French Open semi-final against Rafael Nadal on Friday.</p>.<p>"It looks like a very serious injury but the medical team are still checking it and I will keep you updated," the German world number three said in a video message released by Roland Garros.</p>.<p>Nadal was 7-6 (10/8), 6-6 ahead when Zverev injured his right ankle and had to be taken off the court in a wheelchair before retiring from the match.</p>