Nigel Adkins told the media that he had 26 outfield players on the training pitch on Thursday, although not all are available for selection.
Amongst the group were full-backs John Brayford and Bob Harris, who are battling their way back from lengthy injury problems.
"We've never had as many as 26 outfield players out on the pitch together this season," said the United chief. "They are not all ready and available but it is a step in the right direction. It is pleasing.
"We are conscience of players breaking down when they return. Ryan Flynn had a setback, John Brayford did a couple weeks ago, whilst we are guarding against that with the likes of Matt Done and Paul Coutts at the moment, because they have been out for long spells too.
"John Brayford is not ready yet, hopefully he can have two or three weeks of consistent work to get him to a stage where he can play for the U21s again, and that's a similar situation with Bob Harris.