Deals for out-of-contract players can be struck beyond the deadline and there is plenty of experience on the free agent market.
It was not a quiet window for the Reds, who recruited three new faces to join their promotion push. The first was towering defender Donovan Pines, who joined having previously plied his trade in the MLS.
Next through the door at Oakwell was defender Josh Earl, who sealed a deadline day switch from Fleetwood Town. The final arrival of the window, midfielder Conor Grant, was not unveiled until the day after the deadline.
It remains to be seen whether Barnsley will make any free agent additions, although they may have to act fast if they do want reinforcements. The most talented unattached players are likely to attract plenty of interest, so offers may need to be tabled quickly.
Here are 21 free agents the Reds could potentially target.
