United boss obtained the signature of 33 year old Gerrard after the keeper was released by Nottingham Forest this summer; and without a club was able to sign outside the transfer window.
Paul Gerrard said: "I'd had a couple of chats with clubs but nothing came of it. I was training on my own before Neil Warnock gave me a ring.
"It suited both me and the club and, in the end, I've signed until the January transfer window."
This will be the keeper's second spell at Bramall Lane having played 16 times for the Blades whilst on loan from Everton during the 2003-04 season. It is hoped that both Gerrard and Ian Bennett will provide adequate cover for the currently injured Paddy Kenny.