Warnock, whose Championship side are currently topping the table visited China for pre-season friendlies though also sent out scouts to Hungary to view potential talent but came back with nothing.
Warnock told www.sufc.co.uk; "We're intensifying our search for foreign players because it's becoming increasingly difficult to find available English players who would make us better than we already are.
"So one or two of us will be going to watch matches abroad. It won't be a one-off mission. We'll make regular trips overseas to watch some of the players our scouts have identified,"