Out-of-favour striker Oumar Niasse is edging closer to a loan move to Cardiff which would leave the Toffees boss with Dominic Calvert-Lewin, Cenk Tosun and winger-turned-forward Richarlison as his options up front.
The trio have hit just 17 goals between them - Richarlison has scored nine - but there will be no reinforcements coming in January.
"It is not my job to change my mind," said Silva.
"When you asked me the last few weeks the possible players coming or not in the market, I told you that you just can't sign someone if someone leaves the club or we sell someone.
"We don't have the financial conditions to go in the market, (that) is the feedback I have at the moment. I have to find different solutions." That will not prevent Niasse leaving if a deal is thrashed out with their struggling Premier League rivals.
The 28-year-old Senegalese has played a bit-part role at the club since arriving in a £14 million deal in January 2016, going out on loan to Hull two years ago.
He has made just seven appearances this season but only one start and has featured in the matchday squad just 10 times in 25 games this season.
"Strong interest coming from Cardiff. But nothing is done yet," Silva added.
"We have to wait to see if the teams go this way or not, but I can tell you the interest is strong."
Silva, however, is not planning a huge clear out and insists the likes of Phil Jagielka, currently injured, and midfielder Morgan Schneiderlin still have a future at the club.
Club captain Jagielka has made just two appearances, the last in November, and has featured in the squad a total of five times.
Schneiderlin's record is not much better, with nine appearances, all but one of which came before November, and 11 squad selections in 25 matches.
"Their future is here with me, every day working hard like they are," the Portuguese manager said.
"Jagielka started playing the first game, Schneiderlin played the first few games. After that it is a matter of performance. 'Their future will be here to play again and help us win matches.
"Jagielka is our captain and is an important player in our dressing room. Morgan is a senior player also.
"I can only put 18 in the squad list. If you look at other squads in the Premier League and they play with two central defenders, most of them, one on the bench and the other one will be out. I think it is not just us."