England midfielder Isobel "Izzy" Christiansen was facing a women's World Cup fitness battle on Friday after undergoing surgery on an ankle injury picked up on international duty.

The 27-year-old was hurt just before half-time in Tuesday's final of the She Believes Cup in which England defeated Japan 3-0.

Her French club Lyon said Friday that it was not possible to say how long she would be sidelined.

Former Manchester City star Christiansen has 16 caps for England who will feature in the women's World Cup being played in France between June 7 and July 7.