The Reds, who ended a four-game losing streak when they outplayed Reading in a 1-1 draw on Tuesday night, brought in Stoke goalkeeper Jack Butland and Norwich midfielder David Fox last week - and Flitcroft is not done yet.
"We are trying to add to what we are doing, we have added some players and evolved a squad," he said.
"We have got one loan left which will give us five. I might potentially carry six and then shuffle the pack, but at any stage of the season you have got four or five injuries and you have got to cover that."
The Reds boss has been unable to call on defender Lewin Nyatanga this season as he battles a knee injury.
The summer signing is in recovery, but is not expected to be pushing for a return any time soon.
"He has struggled to get going," Flitcroft added. "He has got a bit of a knee problem so he had a scan on it and it showed some fluid on the back of the leg.
"It will just take patience and time."
Flitcroft had better news on goalkeeper Luke Steele's back injury though, adding: "He's developing well, he's responding to treatment, but I can't put a timescale on a return."