Sean Dyche claimed Everton do not have the finances to make significant changes in the transfer market.
Everton were hammered 4-0 by Tottenham on Saturday, following on from a 3-0 defeat to Brighton last week.
Those defeats have left the Toffees rooted to the bottom of the early standings.
Everton have signed five players this summer, but with just a week remaining in the window, Dyche does not expect many more incomings.
"There aren’t any finances to change things, this is what we are," said Dyche when asked about potential signings.
Speaking to Everton's media channels, Dyche added: "It's a strange situation here. In my 19 months here, we build something, we have to go back down the hill to remind ourselves of the challenge and go back up again.
"Look at the last three seasons, we're trying to rebuild a team. I still expect more, I don't expect the first two games to go like this, that's fair and definitely my responsibility.
"The Everton fans don’t want excuses, I'm not prepared to make them, at the end of the day we've still got players here I feel can operate at this level.
"We're a good group of people, working hard so let's go and take it on and that’s got to change."
Everton are just the second side to lose their opening two Premier League games in three consecutive campaigns (excluding when a relegation was suffered in between), after Bournemouth between 2015-16 and 2017-18.
And after last week's capitulation at home to Brighton, Everton have lost their first two games in a top-flight season by 3+ goals for the first time in their history.
The Toffees' prospects in the market may change if they are able to sell players in the next week, with Dominic Calvert-Lewin among those linked with a move away.
Calvert-Lewin is out of contract at the end of the season, and Dyche confirmed the club would likely have to listen to offers for the striker should they come in.
Neal Maupay, meanwhile, is reportedly of interest to Marseille.