The Madrid Masters was hit by another high-profile requirement on Thursday, with injured Daniil Medvedev pulling the plug after losing the first set of his quarter-final to Jiri Lehecka 6-4.
The fourth seed needed an early off-court visit to the trainer for a leg problem but hung in until the 10th game of the opening set when he dropped serve and then threw in the towel due to his condition.
He was also treated during the changeover two games later at 4-3.
The withdrawal followed by 24 hours a pullout from top seed Jannik Sinner, who complained of hip pain.
The top half semi-final at the Caja Magica will be played between Canadian Felix Auger-Aliassime and Lehecka, neither of whom completed a last-eight match
No. 31 Lehecka will be playing his first semi-final at the Masters 1000 level.
