Sheffield United defender Danny Cullip has joined Watford on loan, with Hornets striker Danny Webber moving the other way in a loan swap deal.
The swap comes with the option for the deal to be made permanent in the summer if both clubs are in agreement.
"Danny Webber made it clear he wanted to join us," Blades boss Neil Warnock told his club's website.
"We are delighted Danny Cullip has joined us. He is vastly experienced," said Watford chairman Graham Simpson.