Derby County boss Paul Warne has explained the reason for a delay over a transfer for a goalkeeper, as talks continue over three options. The Rams have spent all summer in search of a new number one, following an exit for Joe Wildsmith as a free agent. Josh Vickers has been the only senior option in the squad during pre-season, following a campaign of competing for his place in the team. The former Arsenal man is expected to have plenty of competition though, with Warne in search of another goalkeeper option. Plenty of names have been linked with Derby, but are yet to make their way to Pride P…