Brendan Rodgers said it is "clear to see" his Leicester side have been weakened this summer but said he has full trust in the club's board over their transfer strategy.
Rodgers' side remain bottom of the Premier League after a 1-0 defeat to Manchester United on Thursday night, and Wout Faes, signed on Transfer Deadline Day, but too late to make his debut in that game, is their only senior summer signing.
That comes despite the sale of Wesley Fofana to Chelsea for more than £70m and the loss of club captain Kasper Schmeichel to Nice for an undisclosed fee. In his programme notes for the United defeat, chairman Vichai Srivaddhanaprabha blamed the need for "difficult, short-term decisions" to "protect the club's long-term interests."
Speaking after their fourth defeat in a row, their worst spell of league form since February 2017 - a run which cost Claudio Ranieri his job - Rodgers said: "I'm happy the window is shut, it's been a huge distraction for us. You'll have read the programme notes and seen the situation the club is in.
Leicester chairman Vichai Srivaddhanaprabha's programme notes
First and foremost, Leicester City's overall financial
position is entirely secure and underpinned by my ongoing personal commitment and that of my family.
The club is as safe in our hands as it has been every day for the last 12 years. It's our commitment to that responsibility that drives every decision we make. Sometimes, that commitment means making difficult, short-term decisions that protect the club's long-term interests, such as our approach to this summer's transfer window.
Due to an increase in our net spend over recent seasons, some measures were necessary to ensure we manage our compliance with the game's sustainability regulations. While we continue to build our wider revenue streams to compete with the established elite in the long-term, our short-term means of offsetting such expenditure is generating profits through player trading.
We did that successfully for five straight summer windows before 2021, where we opted to make further investments in the squad without a significant sale. This summer, we couldn't risk unbalancing that equation further, so we decided space would need to be made in the squad before new additions could be brought in.
"To have to watch virtually every club in the top five leagues get players in and for us to not be able to improve that was difficult as a manager and players. Players want to compete; this group has shown they can compete but we needed help and unfortunately we haven't been able to get that.
"In terms of results, it's my responsibility. We should have won by now, we've been in really good positions in a couple of games and not seen it through so I totally understand it, the supporters want to see their team win and if they're not, they'll tell.
"We won't hide behind the rock and go away, we're ready to fight but it's going to be really important that the supporters get behind the players because it's a really challenging situation not being able to freshen up this team. We need their help to push the players through.
"I think it's clear to see [that the squad is weaker than last year]. I came to Leicester to compete and in the first few years we were able to do that but in the last couple of windows we've been unable to add to the squad.
"What's most important is the sustainability of the club. I would have loved to have added five, six players to add to the quality of the group but if you can't do it I respect that. I have to do the very best with the resources I have.
"I've loved every minute of being here. It's the longest I've been at a club and that's because of the players and the ownership. They've given me every support. My challenge here was to disrupt the market in the first two years, we were able to do that, winning the FA Cup and Community Shield, and you want to build on that but we haven't been able to do that.
"I trust the board here if they're telling me we can't do that, then we can't. It's frustrating but I respect the people here."
Rodgers, who is now into favourite as the next Premier League manager to be sacked, said he was "relishing" the challenge of keeping his squad competitive this season, despite facing early pace-setters Brighton and Tottenham in their next three games.
"I'm so looking forward to the window shutting and taking on the challenge," he said. "I've only ever been in this position once when I when I went into my first job at Watford, we were in the bottom three and one of the things we did do in the January window was galvanise the squad and bring players in.
"That saw us through and we finished the season well. I'm going to relish it and certainly won't be shirking the responsibility."
Ten Hag: Too early to say we've turned corner
Despite a third win in a row and back-to-back clean sheets, Erik ten Hag struck an air of caution after United's first victory against Leicester in five attempts.
"Maybe it's too quick to say [we have turned a corner]," he said. "We're happy with it, we're building a team and a squad who are sticking together, fighting for each other, they co-operate and if you do that, you get the right results. We have to step it up further, and Sunday will be a really good game, a really good test, so we're looking forward.
"I'm happy with the clean sheet. When our 11 on the pitch who defend and attack together, when you have the team, the energy, you see what you can achieve."