Yannick Bolasie may not play for Everton again until the end of 2017, with manager Ronald Koeman confirming that the winger would undergo a second operation on his knee.
The 27-year-old, who joined from Crystal Palace in August for an initial fee of 25 million pounds ($31.37 million), played every game for Everton until injuring his anterior cruciate ligament against Manchester United on Dec. 4.
Bolasie had surgery in the third week of December to repair damaged cartilage in his knee, but the ACL injury requires another operation.
"Yannick will have a second surgery at the beginning of March," Koeman told reporters ahead of seventh-placed Everton's clash with basement-side Sunderland on Saturday.
"The surgery was expected because his first surgery was about the meniscus and now what will happen at the beginning of March is about his cruciate.
"It is difficult to put a timescale because normally a cruciate can be six, seven or eight months. We had to repair the meniscus and then wait until his knee was ready to have the second operation."
Striker Romelu Lukaku, who missed Everton's recent warm-weather training camp in Dubai with a minor calf problem, is training with the squad ahead of the visit of Sunderland, while midfielders Kevin Mirallas and James McCarthy are also fit.
Mirallas (groin) and McCarthy (hamstring) missed Everton's goalless draw at Middlesbrough on Feb. 11.