Newcastle face a fight to hang on to France full-back Mathieu Debuchy as interest mounts in his signature.
Press Association Sport understands suggestions that a move to Arsenal is all but done is premature, but there has been contact between the two clubs.
In addition, long-time admirers Paris St Germain, who signed the 28-year-old's close friend Yohan Cabaye from the Magpies for £19million in January, retain an interest, and reports have suggested Marseille too are monitoring his situation.
Newcastle boss Alan Pardew has no desire to sell Debuchy, who signed a five-and-a-half-year deal when he joined the club from Lille in January last year for around £5.5million.
However, the player has spoken of his desire to play Champions League football once again, something Newcastle cannot offer him, and rather than try to hold on to a potentially unhappy player, they could be prepared to cash in - but only if the price is right.
To that end, potential suitors have been warned that they will have to meet the club's valuation - in the region of £12million - if they are to prise the France international, who is currently on World Cup duty in Brazil, from their grasp.
Contingency plans are being drawn up should that prove to be the case with Toulouse's Ivory Coast international Serge Aurier among the candidates to replace the Frenchman.
The Magpies have also been linked with Arsenal full-back Carl Jenkinson and Manchester City's Micah Richards, although the latter's current salary may prove an obstacle to any move.
Debuchy's situation is an unwelcome distraction for Newcastle, who were already facing a sizeable rebuilding job with strikers and attacking flair the priority.
They went some of the way to addressing that situation on Tuesday evening when Ajax skipper Siem de Jong, the older brother of Borussia Monchengladbach striker Luuk, who spent the second half of last season on loan at St James' Park.
He becomes the club's third summer signing after Jack Colback and Ayoze Perez.
De Jong, 25, scored 78 times in almost 250 appearances for the Dutch club, and that is a strength he hopes he can bring to Tyneside.
He told nufcTV: "I hope to bring a lot of attacking play and goals.
"At Ajax, I scored quite a lot of goals as an attacking midfielder - sometimes as a striker - and I hope to do that here too. I want to help the team be as good as it can be."
De Jong has spent the last three years learning from childhood hero Dennis Bergkamp, Ajax's assistant manager, who famously scored one of the best goals in Barclays Premier League history for Arsenal at St James'.
He said: "Dennis Bergkamp was my hero growing up. I watched him a lot. He came to the Premier League with Arsenal and was a great player for them.
"The way he played, he was something special, and the goals he scored were great too.
"It was great when he joined Ajax as a coach and I found it pretty funny to be working with my hero.
"I learned a lot from him. He was assistant coach, but also was the forward trainer, so I picked up some good things from him and it was nice to work with such a great player."
Newcastle remain in the market for out-and-out frontmen with Loic Remy, who spent last season on loan with the Magpies, expected not to return, Luuk de Jong having returned to Germany and Shola Ameobi's contract having expired.
Hertha Berlin's Pierre-Michel Lasogga and Lyon's Alexandre Lacazette are still in their sights, as too is Montpellier midfielder Remy Cabella, a long-term target.