Scans confirmed on Tuesday the 20-year-old had damaged her ACL, medial cruciate ligament and meniscus when she attempted a tackle in the 10th minute of the Sky Blues' 4-2 win over Wellington on Sunday.

Fenton will have surgery in April and will be sidelined for nine to 12 months.

The Newcastle product had been chasing a Matildas call-up ahead of the Paris Olympics, impressing with her ability to play on the left and right side of defence.

Sydney are also two wins away from recording a league-wide record of four consecutive premierships and were already without defender Nat Tobin.

The influential skipper tore her ACL in October.

"It's a kick in the guts and not something you want to hear, especially coming to the end of the season where we are aiming to make history," Fenton said.

"Obviously it hurts. Knowing that I have Nat makes me feel a lot better.

"It sucks for her as well and she shouldn't be going through it either, but I'm glad I have someone like her to help get me through it."

Though Fenton's injury is a heavy blow to the team, Sydney coach Ante Juric is confident his side can claim another title.

"We've used these setbacks before as motivation to perform for our injured players, and we'll be looking to do that in the final matches of this season," Juric said.

"Our heart goes out to Kirsty, because she's an important person and important player in the team.

"It's disappointing to have her out and for the team to suffer another major injury."

Australian Associated Press