Real Madrid defender Sergio Ramos played on after having fractured his nose in Saturday's draw with Atletico Madrid.
Los Blancos' captain was kicked in the face as Lucas attempted to reach the ball, and was left bleeding profusely.
He was treated on the sidelines and reemerged with two cotton wool buds placed up his nostrils.
Ramos played the remainder of the first-half, but was forced to withdraw after the break when it was confirmed he had suffered a fracture.
The 31-year-old has precedent for such acts of resilience. Having broken his nose in a 2007 meeting with Bayern Munich after clashing with Roy Makaay, he played for three months without an operation.
Three days after breaking his nose in Bavaria, the former Sevilla centre-back scored the opening goal against Barcelona at the Camp Nou.
Real Madrid were adamant that a penalty should have been awarded for the challenge on Ramos against Atletico, although the referee and his assistants were unmoved.
And had a spot-kick been awarded, it might have made all the difference. The game was one of fine margins, but ultimately ended goalless with neither side able to create enough clear opportunities.
It left Zinedine Zidane's side ten points behind league leaders Barcelona with just 12 games played.
Real Madrid have had a better time of things in the Champions League, but they will be keenly aware that a victory against APOEL is essential.
Ramos is set to be evaluated by doctors to see if he requires surgery, and is likely to stay at home and sit out his side's trip to Cyprus.