Atletico Madrid manager Diego Simeone has said that the summer transfer window makes him "nervous" as he looks to keep his best players.
Forward Antoine Griezmann has reportedly signed a new contract with Atleti following strong interest from other European clubs, but Simeone says that he is still wary of potential bids which could weaken his side.
"In football, the most dangerous month is August," he told AS. "We have to be on full alert at all times. Let's hope nothing unexpected happens. As far as we are concerned the squad is 99% closed.
"[The squad] will be [100% closed] from midnight on August 31. Until the transfer market closes, you can't say anything. August always makes me feel nervous. It worries me a lot."
Simeone has so far seen the likes of Arda Turan, Mario Mandzukic, Miranda and Mario Suarez all depart the Vicente Calderon this summer, but has been successful in bringing in Jackson Martinez, Stefan Savic, Yannick Ferreira Carrasco and Luciano Vietto, as well as securing the return of Filipe Luis from Chelsea.