Partey, 27, joined Arsenal in the biggest deal of deadline day after the Gunners paid his €50m release clause.
Due to the pandemic, La Liga has placed financial controls on clubs, allowing them to spend only 25% of what they earn.
This largely explains why Barcelona, Real Madrid and other Spanish clubs spent very little this summer.
And it also means that Atletico would only be able to commit €12.5m to a new midfielder in the next month.
La Liga has a 30 day period that allows clubs to sign a replacement if a player’s release clause is paid.
Will Partey be replaced?
Speculation is rife as to who Atleti might sign to replace Partey, but the reality is far less exciting.
According to AS, despite links to Campana (Levante), Kongdobia (Valencia), Arambarri (Getafe) and Merino (Sociedad), Atletico are unlikely to spend.
In fact, the Rojiblancos believe they brought in a replacement yesterday when Lucas Torreira arrived.
Torreira’s loan move from Arsenal was overshadowed by Partey’s big money switch.
And the Madrid club will have the chance to make 24-year-old Torreira’s stay permanent for around €20m.
However, if Atleti decide to move for another midfielder this month, he will have to cost a maximum of €12.5m.