Man City's Nasri suffers from serious injury
The Frenchman stayed down for several minutes following a heavy challenge from Magpies defender Mapou Yanga-Mbiwa, who was booked for the lunge and quickly substituted.
“[It's] Very serious because I think it was a very unfair kick from the player of Newcastle it was directly red card. I don’t understand why he [Yanga-Mbiwa] wasn’t sent off," Manuel Pellegrini said after the match.
“Samir Nasri has a problem with his medial ligaments, we’ll see tomorrow how serious, but I don’t think it’s a nice thing, I think it’s serious.”
Nasri looked in severe pain as he was lifted from the field, and will be hoping to avoid an injury similar to the one which will keep Theo Walcott out of this summer's World Cup.
Walcott was ruled out for six months with an anterior cruciate ligament injury sustained during the FA Cup third round clash with Tottenham last Saturday.
Newcastle had earlier had a goal controversially ruled out for offside, which sparked a touchline row between managers and coaches, and caused outrage among home fans.
Alan Pardew confronted referee Mike Jones on his way to the dressing rooms at half-time, telling him, "the linesman is right, you are wrong," after Jones had ruled that Yoan Gouffran was standing in an offside position as Cheick Tiote's shot crashed in from outside the area.
City moved top of the Premier League thanks to an early Edin Dzeko goal and a stoppage-time clincher from Alvaro Negredo.