The Argentine is frustrated that los Rojiblancos are yet to bring in any new players - despite the money-spinning sale of Radamel Falcao to Monaco
The Argentine is frustrated by the fact that los Rojiblancos are yet to sign a single player, even after the multi-million euro sale of star striker Radamel Falcao to Monaco.
Consequently, Simeone is urging the club's directors to splash the cash if they are to build upon last season's Copa del Rey success and continue to challenge la Liga's top two.
"Real Madrid bought Isco for €30m and Barcelona have already bought Neymar," the former midfielder is quoted as saying by Marca.
"But we have not yet signed a player. Solutions are being sought to remain competitive but we must improve the squad we have.
"We still have not been able replace Falcao. We're looking for a striker and midfielders who can give us a qualitative leap.
"Last season we were in the Europa League but now we will play in the Champions League, which is different. It is difficult when you are unarmed and we need weapons."
Simeone does not expect Atletico to break any transfer records but he does feel that significant investment in the squad is essential for the club's development.
"I do not want nor do I imagine Atletico spending €50m on a player," he explained. "But you can improve the team without breaking the bank."
Despite his obvious frustration, though, Simeone insists that there is no chance of him leaving the Vicente Calderon.
"I do not hesitate about staying because I believe in the work we are doing," he declared. "We are going to remain competitive."
Simeone has overseen a dramatic upturn in Atletico's fortunes since taking charge in December 2011.