Screams of agony pierce Wimbledon after tennis player suffers horror injury on court.

Crowds of tennis lovers have been left in shock after US women’s player Bethanie Mattek-Sands was left screaming in agony on court during her Wimbledon match on Thursday.

“Help me! Help me, please! I need help, please!” the 32-year-old screamed as fans helplessly looked on from the stands.

The injury occurred during the Wildcard entrant's third set of her second-round match against Romania's Sorana Cirstea. The American fell awkwardly and almost immediately began clutching her knee and writing in agony.

F**k!” she howled, screaming for help. "F**k it hurts, f**k me it hurts.

Within moments, Cristea had crossed the net in an attempt to help her competitor, later saying, "She kept saying, Sorana help me, Sorana help me ... I was trying but of course, I felt useless.”

Cristea added, “I’ve never seen anything like this in my life, such an injury."

Medics responded to the court within a minute, but it took a further 20 minutes for Mattek-Sands to be removed from the court, something the tournament is now being criticised for.

While treating Mattek-Sands on court, The Sun reports she could be heard screaming, "Have you given me any f***ing painkillers? These painkillers are not working. Please knock me out, please knock me out.”

"I tried to comfort her as much as I could but, I mean, you could feel the pain... it felt like so long."

Wimbledon officials responded, releasing a statement that read, "The first response to Court 17 was within one minute, by a qualified ambulance technician. The player was kept on court while pain relief was given."

A club spokesperson also confirmed to AAP that a courtside stretcher was available but wasn't brought out until Mattek-Sands had been administered with painkillers to numb her pain.