US Open champion Bianca Andreescu has withdrawn from the WTA Finals with a left knee injury.

Andreescu was forced to retire mid-match against Karolina Pliskova on Wednesday night after landing awkwardly while returning a serve.

The Canadian teenager’s loss to Pliskova as well as defeat at the hands of Simona Halep in her round-robin opener left her out of semi-finals contention.

“I had a scan Thursday to check my knee after last night’s match, and unfortunately the results show that I need to withdraw,” Andreescu said.

“It was amazing to play here in Shenzhen at the end of this incredible season. I’m very disappointed to not be able to finish the year on my terms.

“But I am hopeful I will have more chances to play here in the future.”

Alternate Sofia Kenin will replace Andreescu for Friday’s match against unbeaten defending champion Elina Svitolina.