Steve McClaren has told Jose Mourinho to keep his hands off Georginio Wijnaldum after the Chelsea boss admitted his admiration for the player.
The Magpies paid PSV Eindhoven £14.5million for Wijnaldum earlier this summer, but Mourinho has already hinted at a future move for the midfielder by admitting he would 'fit the bill' for the Premier League champions.
But Wijnaldum, 24, was always in McClaren's sights after the midfielder "killed'' his FC Twente side during the new Toon boss' time in Dutch football.
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Wijnaldum signed a five-year deal when he became the third most expensive player in Newcastle's history behind Michael Owen (£16m) and Alan Shearer (£15m).
Asked about Mourinho's view that Wijnaldum is good enough for the Blues, McClaren said: "He will be - but hopefully not for another four or five years!"
McClaren, whose Newcastle side begin their campaign at home to Southampton on Sunday, does agree with Mourinho's assessment that Wijnaldum will be a big player in the Premier League.
He said: "I think he brings energy, tempo and quality on the ball. He can score goals and has adaptability in midfield. He can sit, go forward, go box-to-box and play No.10, so he has that flexibility.
"I knew him very well from my time in Holland - he killed my team a few times. He is one who can certainly adapt to the Premier League."
Wijnaldum also hopes to impress at St James' Park so that the fans take him quickly to their hearts.
He said: "I am more excited than yesterday. What I hear from friends and people here at the club is that the fans are really excited for me to sign and that gives me a good feeling.
"When I came here the people were really nice with me and I met people and they were happy I signed with the club. I have more of a better feeling. Now I look forward to the first game and I am happy it is at home to Southampton.
"I hope to [become a hero at Newcastle]. I was in their hearts at Feyenoord before I went to PSV, then they were mad at me.
"The PSV supporters loved me also and when you play some bad games the supporters can help you out and that is important for the player if the supporters help you when it is going bad. That is what I hope."
Wijnaldum has been joined on Tyneside by Serbia striker Alexsandar Mitrovic, 20, and McClaren sees similarities between him and Chelsea's Diego Costa.
He added: "He has that edge. He certainly likes physicality and there aren't many who like that these days.
"He's one for now - but I feel he is definitely one that will mature further in the future."
But McClaren rejects the comparisons with Liverpool misfit Mario Balotelli.
He said: "Mitrovic is totally unlike him - he has never skulked around the training ground and he's always smiling.
"He's got those assassin's eyes. He came with a reputation but he's worked hard and been great."