Manager Gary Johnson wants to cut his Northampton Town squad by 10 players.
Johnson oversaw wholesale changes at Sixfields in the summer, but the 18th-placed Cobblers have struggled in League Two this season.
"We've got a squad that needs to be shorter by at least 10 players," he told BBC Look East. "So there's quite a bit of work to be done.
"You have to deal with the mistakes but you have to keep searching for the side that's going to get you promotion."
Since his appointment as Northampton boss in March, Johnson has made 24 signings including loan deals.
And the former Bristol City manager admits not every new arrival has lived up to expectations.
"You bring players in believing they're good enough and often they are good enough," he said.
"But sometimes it doesn't happen for them for one reason or another. You can't leave it too late before making some changes.
"All clubs will say managers have brought in some poor players and you don't expect them to be poor when you're bringing them in.
"However, managers that are successful tend to have brought in more good players than bad. You're never going to get a 100% record."