Sergio Ramos has apologised to Milan Havel after he left the Viktoria Plzen winger with a bloodied nose during Real Madrid's 5-0 Champions League victory on Wednesday.
Karim Benzema scored twice in the rout, further restoring morale for the European champions under their interim boss Santiago Solari.
But captain Ramos was again at the centre of a controversial moment with the scoreline at 0-0.
Haval required treatment as blood poured from his nose after Ramos caught him with a flailing arm.
He was eventually substituted seven minutes before half-time and Ramos tweeted to accept some culpability for an incident where referee Deniz Aytekin took no action.
"A victory to build on and also to learn from," he wrote.
"Football always teaches you things and tonight I shouldn't have gone into the challenge like that.
"Milan, it wasn't my intention to injure you. Get well soon."
Ramos was criticised for his part in the incident that left Liverpool star Mohamed Salah with an injured shoulder during last season's Champions League final, which Madrid went on to win 3-1.
The holders are top of Group G with nine points from four matches this term.
