The Ghana international has suffered a muscular injury and while it is not thought to be serious, he is now expected to sit out of the battle at the top of the table, The Athletic report.
Partey has been one of Arsenal’s most influential players this season, playing a key role in their rise to the summit of English football.
He has started 18 of their 21 league games this season.
His absence could mean a starting role for Jorginho, who joined the Gunners from Chelsea at the end of the January transfer window.
Arsenal are already without the injured Mohamed Elneny, who would have been expected to step in for Partey. Reiss Nelson, Emile Smith Rowe and Gabriel Jesus are also on the absentee list.
Arsenal lead City by three points ahead of kick-off, having suffered a defeat and a draw in their last two games against Everton and Brentford respectively.
Defending champions City can leapfrog them into top spot with victory at the Emirates tonight.
But a win will see Mikel Arteta’s side restore a healthy lead at the top with a game in hand on their rivals.
While tonight’s fixture is the battle between the league’s top two sides, City boss Pep Guardiola has played down the ramifications of tonight’s result, insisting third and fourth place Manchester United and Newcastle United are still firmly in the title picture.
Asked if he considers United and Newcastle as serious title contenders, Guardiola told a press conference: ‘Yeah, they are there.
‘There are a lot of points to play for. We don’t know what can happen in the next weeks.
‘I always have the feeling, especially now with European competitions back and FA Cup around the corner, the last eight to 10 games are going to decide the title.
‘We have to try to be there in that moment and then have to make the last effort to try to achieve it.’