However, the crisis seems to have passed after the Toffeemen today secured ex-England international Martyn for a nominal fee.
Meanwhile, Blades manager Neil Warnock has been full of praise for the 30-year-old loanee.
"I'm amazed I've been able to get him. Paul is a top-quality keeper who I've admired for a long time".
"Everton were great about it because David Moyes, their manager, was worried it might leave him short of cover".