David Moyes has admitted he might have to "take a few more blows" in his first season as Manchester United manager, warning there will be more difficult times to come as he tries to make the handover from Sir Alex Ferguson as seamless as possible.

Moyes, who missed out on several targets during the transfer window, said he was "shocked" by the 4-1 thrashing against Manchester City on Sunday, and indicated for the first time that the team he inherited from Ferguson had obvious deficiencies. The former Everton manager has previously talked about a side who are capable of winning the Premier League and Champions League, but now appears to have his own doubts about their quality. "I think a lot of people thought Manchester United [winning the title] last season, that it was probably the form of the other teams that was poor," he said.

Moyes had not initially planned to hold a press conference to preview Wednesday's Capital One Cup tie against Liverpool but changed his mind after the City defeat. "I think it's important that I took the punches," he explained. "I've taken the punches and I'm happy to do that. Not for a minute did I think this Manchester United job was going to be an easy job. There will be days like we had on Sunday and there might be more of them because we are in a period where there will be transition, there's a new manager for the players and, in turn, there will be new players.

"I don't think it's actually the squad, I think we've got numbers. I think maybe we've got work to do to bring in players not for the squad but to go right into the team. It's not necessarily the squad players we needed, we needed one or two who might have gone in [to the team]. That will happen. But going back to that transfer window, we always said it was going to be a tough one and it was going to take a little bit more time.

"It does mean I may have to take a few more blows, definitely. Maybe even more than that. Maybe all season I have to take a few blows but I knew this was going to be the case because I was taking over from a great manager and it was always going to take time for me to get my own ways and change things round a little bit."

Liverpool have already beaten United this season and Moyes, still missing the injured Robin van Persie, must decide whether to stick to the club's usual policy of using younger players in this competition or fielding a stronger side than he had originally planned to lessen the risk of a bad few days getting any worse.

"I think the team has played well [overall]. If you were being really fair you'd have to say that Manchester United have played well, but that [City] was a poor performance, really. We have not played badly except at Manchester City.

"We looked quite easy to play against, which is not the norm for Manchester United. I think the one thing here is that any team should always have a hard game against Manchester United. But I thought we were just too easy to play against. It was the basics. I hadn't seen that before. I also have to say I hadn't seen that level of performance from Manchester City either. But I hadn't seen that poor a performance from us, so there was quite a contrast."

City, by Moyes's own admission, might have made his first experience of the Manchester derby even more harrowing, the United manager accepting that Manuel Pellegrini's team had looked capable of scoring six or seven when they took a 4-0 lead early in the second half. "I'm not daft. I know we were in real danger at that moment. I took a little bit [of encouragement] that we tried to make sure nothing went any further because at that time it could have. But, by that time, Manchester City knew they didn't have to do any more, so I'm also aware of that."

Van Persie is still troubled by a groin injury, with Moyes rating him as having only an "outside chance" for Saturday's game at home to West Bromwich Albion.

"You just hope there will be a reaction and I'm sure there will be," United's manager continued. "When you've got the players we have, I can see it written all over their faces how they feel.

"It doesn't really matter whether I have seen a reaction [in training]. The reaction has to be seen when you people [media and public] can see it. I'm still getting to know all the players here. I'll get a chance to know more of them this week, and hopefully they will show what they can do."