Tottenham have made enquiries about the availability of defender Chris Smalling, with Everton also said to be interested.
The 30 year old England international is currently on loan in Italy with Serie A side Roma, and has made a big impression with his adopted club, whom he has even captained on several occasions.
Roma have asked about signing him permanently, but United have increased the fee for him to £16.5 million, and, once his wages are added into the equation, he will cost them £33 million in total.
Now, it looks like they could be priced out of the market for him unless they secure Champions League football next season, something which is looking unlikely after a recent run of poor results.
That has put other clubs on notice, with Spurs believed to be leading the pack, with Jose Mourinho still looking for somebody who can solidify a defence that leaks too many goals.