Diego Simeone insisted that Atletico Madrid must 'stay calm and keep working' after his side fell to a surprise 1-0 defeat away to Real Betis in La Liga on Sunday.
New signing Alvaro Morata made his debut for Los Rojiblancos, but the on-loan Chelsea striker's presence in attack was not enough to prevent Atletico from suffering a shock defeat in Seville, courtesy of a second-half penalty from Sergio Canales.
The defeat left Atletico six points adrift of league leaders Barcelona, and Simeone said after the game via the club's official website: "Betis are one of the best teams in La Liga, they're in the Copa del Rey semi-finals and they play great football.
"They scored their penalty and deserved to win."
Antoine Griezmann came closest to drawing the scores level after the visitors fell behind on Sunday, though the Frenchman shared his usual spotlight with strike partner Morata, who made his first appearance since joining the La Liga side on loan in January.
The Spaniard failed to convert the chances that fell his way in the match, but Simeone said of his new forward: "Morata played very well, with great enthusiasm. We hope he can score soon.
"We have to stay calm and keep working."
Atletico's schedule does not get any easier, as Simeone's side prepare to host local rivals Real Madrid in a huge derby clash at the Wanda Metropolitano next Saturday between two sides looking to cut the gap at the top of the La Liga table.
Barcelona failed to extend their lead at the top as they were held to a 2-2 draw at home to Valencia on Saturday, whilst Real Madrid were the only side in the top three to win over the weekend as Los Blancos recorded a comfortable 3-0 win at home to Alaves on Sunday.