Brek Shea's proposed move to Stoke City has been plunged into doubt and may not be completed during the January transfer window.
Shea, 22, had been expected to begin a week's training with Tony Pulis's squad on Monday, but did not arrive at Stoke's Clayton Wood traning ground.
It appears the deal to bring the FC Dallas midfielder to England has hit a snag over his valuation, despite the two clubs agreeing a fee in the region of £2 million.
Under American rules, that figure has to be ratified by Major League Soccer, and ESPN understands the MLS wants a transfer fee almost double that which had been agreed.
The MLS has intervened to place a higher valuation on Shea because of his age and potential, despite him still needing to prove he has fully recovered from an operation to remove a bone from his right foot.
Stoke had been hoping Shea would be able to play in a friendly against Derby County on Tuesday so manager Pulis could assess his fitness.
Pulis has already been asked to shed some of his fringe players, such as Jermaine Pennant and Wilson Palacios, to make room for any new arrivals this month.
He is also waiting on developments in Swansea City’s efforts to sign striker Kenwyne Jones, for whom a £2 million offer has been rejected.
That could yet have an influence on Pulis’s decision on Shea, who was wanted by Arsenal and Fulham over a year ago.
He remains keen to see the midfielder train and spend some time at the club, but may now put attempts to bring him to the Britannia Stadium on hold until the summer.