Barcelona are still unbeaten in La Liga this term, but they could only draw 1-1 at struggling Las Palmas on Thursday night.
On Sunday, the Catalan giants will welcome an Atletico side who have won their last eight matches in all competitions.
The gap from first to second is now just five points, but Busquets has insisted that leaders Barcelona are "still in a privileged position" ahead of the clash at Camp Nou.
"We're still in a privileged position, although the toughest battle will be on Sunday," Busquets told reporters. "These are two points that we dropped at an important moment, but we knew that it was a difficult place to go, even if Las Palmas are near the bottom."
Barcelona have won 10 and drawn two of their 12 home La Liga matches this season.