Flinders is currently second choice keeper behind Julian Speroni at Palace, and a temporary move to the League One strugglers would give him some much needed first team action.
However, it's believed the move is happening with a view to a permanent deal in the summer worth £200,000.
If that's the case then it's safe to assume Warnock has a replacement lined up to act as cover for Speroni. Bulgarian keeper Todor Kyuchukov, who is currently trialling with the reserves, is the most likely option.
Should Flinders make the trip across London to the New Den, he will be the third player this season to do so. Dave Martin and Lewis Grabban have already signed for the Lions, who seem determined to build a side around the Crystal Palace reserves.