Agent Willie McKay says Joey Barton "is committed to Newcastle unless he is told otherwise" amid talk of interest in him from West Ham.
The Upton Park outfit are hoping to capitalise on the uncertainty surrounding the Magpies following the departure of Chris Hughton to try and lure Barton away from St James' Park with a lucrative offer.
Barton has been in sparkling form this season, leading to calls for a possible return to the England fold following a string of impressive performances.
A number of other clubs are thought to be interested in Barton with the 28-year-old having just 18 months to run on his current contract.
Barton's agent Willie McKay has confirmed West Ham's initial offer was rejected by Newcastle and that the midfielder remains committed to the Magpies unless they decide to listen to offers for his services.
"I believe West Ham made an enquiry for Joey and that was rejected by Newcastle," McKay told skysports.com. "Joey is enjoying his football again and he is committed to Newcastle unless he is told otherwise.
"There are other sides interested in Joey as I have had five or six phone calls from teams asking about Joey's availability.
"If these interested clubs make an offer for Joey then it is up to the two clubs to agree a deal and once that happens then we can sit down and discuss a possible move."
