Moyes bought only Marouane Fellaini for United's first team during a three-month transfer window but has now said he needs further reinforcements after starting the season with only seven points from five games.
"I don't think it's actually the squad, we've got numbers," said Moyes ahead of Wednesday night's Capital One clash with Liverpool.
"Maybe where we've got work to do is to bring in players not for the squad but one or two to go right into the team. But that will happen. 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 is a new manager for the players and, in turn, there will be new players as well at different times.
"Yes, 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. I've taken the punches already and I'm happy to do that.
"Not for a minute did I think this was going to be an easy job.
"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 bit.
"A lot of people thought Manchester United won the title last season probably because the form of other teams was poor."
Tuesday's press conference was cut short abruptly when one journalist attempted to ask a question about the form of Ashley Young, who has reached a teammate with only one of his 22 attempted crosses in four Premier League games this season.