Partey, a defensive midfielder, has become a key part of the Rojiblancos set-up this season, having made 15 appearances involving 12 starts in all competitions.
He remains the club's joint-top scorer with four goals this term, and the only member of Diego Simeone's side to have scored in all competitions - La Liga, Champions League and Copa del Rey - this campaign.
"I am very happy with what Partey is doing at Atletico Madrid," Gyan told KweseESPN.
"Since the days of Michael Essien, who was making Ghana proud at Chelsea, we have not had a midfielder who has stood out like this.
"No disrespect to anyone because we have had great midfielders, but since Essien, Partey is the one who is beginning to stand out in Europe."
During his heyday, Essien had spells with Spanish giants Real Madrid, Italian heavyweights AC Milan and French topflight Lyon, but it was during his time at Chelsea that he struck his most accomplishments.
The 34-year-old won the English Premier League on two occasions (2005-2006 and 2009-10, his trophy haul also including four FA Cup titles, one League Cup and two Community Shields and the prestigious Uefa Champions League in 2012.
Since Essien left the big stage, Juventus man Kwadwo Asamoah has been hailed by many as Ghana's biggest midfielder in Europe, although the playmaker spends the most part of his time playing for the Old Lady in defensive positions.