The deputy Ghana captain has missed the Gunners' start to the season after suffering an injury setback during pre-season.
The former Atletico Madrid player is recovering from an ankle injury and could return to action early next month, according to the club.
"Right ankle. Thomas sustained an injury to ligaments in his right ankle during the friendly match against Chelsea on 1 August. Thomas is working hard with the medical team and is aiming to be back in training by the end of August," wrote the club ahead of their Carabao Cup match against West Bromwich Albion.
The London giants have been under intense pressure following their poor start to the campaign, losing two of their opening matches.
Partey will however miss the game against Manchester City on Sunday.
Meanwhile, English-born Ghanaian forward Eddie Nketiah is also out until September.
"Right ankle. Eddie sustained bruising to his right ankle during the friendly match against Chelsea on 1 August. Eddie is working hard with the medical team and is aiming to be back in training in early September," added the club. Read Full Story