Antonio Rudiger has reportedly been told he must sign a contract extension at Chelsea before the club sanction any loan move.
The Germany international defender has been subject of interest from London rivals Tottenham and West Ham, as well as a number of European clubs after falling firmly out of favour with Frank Lampard.
The Hammers are said to be offering Rudiger a season-long loan deal as they look to shore up their leaky defence, but there could also be a permanent way out of Stamford Bridge via Spurs if their move for Inter Milan centre-back Milan Skriniar falls through.
But according to the Daily Mirror, no deal will be sanctioned by Chelsea unless the 27-year-old agrees to a 12-month extension to the 18 months he has remaining on his current contract.
Rudiger was brought into the club by Antonio Conte in a £29m five-year deal from Roma in July 2017, and made 80 Premier League appearances in the following three seasons.
But the centre-back has yet to turn out in the opening weeks of the current campaign and fell further down the pecking order when Brazilian international Thiago Silva arrived from Paris Saint-Germain last month.
And his odds of leaving increased when he failed to make the squad for Chelsea’s Carabao Cup tie with Barnsley, the match in which Silva made his debut.