Samir Nasri was outstanding for Manchester City's victory over West Brom.
Nasri celebrated his first start for almost seven months by scoring a 66th-minute winner as City came from behind to beat the Baggies 2-1 in their Barclays Premier League clash at the Etihad Stadium.
Pellegrini said: "We expected he was going to come back in the middle of April, the doctor said, but we needed to play in the Champions League in February.
"We had just Kun (Sergio Aguero) as a striker as (Wilfried) Bony was injured, so it was important to include Kelechi.
"But, (besides that) I do not think he is able to play (again) in another three days. He has had a long injury."