Speculation has linked Birmingham number one Ben Foster with a season-long loan switch to The Hawthorns and some reports have suggested that the deal could be imminent.
Appleton confirmed that Foster and West Ham shot-stopper Rob Green remain key targets for the Baggies and a goalkeeper should be one of two new arrivals to be confirmed "in the coming days or weeks".
"Hopefully they'll be one or two arrivals in the coming days or weeks but we've probably been hoping that for the last couple of weeks now," Appleton told Sportinglife.com after the 3-0 pre-season defeat at Rochdale.
"The longer it goes on it gets a little bit frustrating but hopefully we're at a stage where we're nearer rather than further away from getting one or two in.
"I'd like to think we're working hard to make that happen but ultimately there has to be agreement between the two clubs and if there isn't agreement between the two clubs we have to look elsewhere."