The Atletico Madrid coach has admitted that it will be hard to replace the Colombian striker, who moved from the Spanish capital to Monaco last week.
The striker netted 28 goals in 34 Liga appearances last season, helping the club to a Champions League place, and Simoene has admitted that finding a suitable successor could be nearly impossible.
"Radamel's achievements are incredibly difficult to top," Simeone told Marca. "I don't know if we're going to lose out in his absence. The statistics are irrefutable and Falcao's are extraordinary.
"I would love another forward to be able to come in and get anywhere close to that."
The capital outfit, however, is looking to bolster up their squad not only up front, but in all positions.
"In defense we'll be looking for a player to give us a greater level of competition, the same in midfield and in attack as well. We need players in all three areas," Simeone said.