Mboko's injury at Queen's could affect Serena Williams partnership

Canadian tennis player Victoria Mboko was forced to retire from her singles match at the Queen's tournament due to a left knee injury, casting doubt on her participation in the doubles event with Serena Williams.

Mboko sustained the injury during her second-round singles match against Czech player Karolina Pliskova. After losing the first set 6-2, Mboko was leading 4-3 in the second when she slipped on the grass court and immediately clutched her knee. Despite attempting to continue after getting up, she realized she could not proceed and retired from the match.

The injury puts Mboko's doubles partnership with the returning Serena Williams in jeopardy. The pair had successfully advanced past their first doubles match and were scheduled to face Leylah Fernandez and Laura Siegemund in the quarterfinals on Thursday.

Serena Williams, 44, is making her comeback on the WTA tour at Queen's, nearly four years after announcing her retirement. She is also slated to compete in doubles at the WTA 500 event in Berlin next week, though her partner for that tournament has not yet been announced.