Newcastle manager Sam Allardyce has warned clubs coveting any of his top players not to bother.
The 53-year-old spoke out after speculation suggested Tottenham are preparing to make an enquiry about England Under-21 captain Steven Taylor, while Aston Villa and Manchester City have been linked with Nigeria striker Obafemi Martins.
Talks over a new deal for Taylor - his contract expires at the end of next season - are deadlocked and both Chelsea and West Ham have also been linked with the 21-year-old.
However, Allardyce's stance was unequivocal after seeing Taylor mature as a player during the first half of the season.
Asked about the Spurs speculation, he said: 'Ain't got a chance. It's as simple as that.
'While they say everybody has got his price, I can tell them that Steven Taylor is not for sale.'
Spurs are understood to have turned their interest to Taylor after receiving no encouragement from Middlesbrough over England international Jonathan Woodgate.
Allardyce was equally dismissive of speculation that Villa and City could be on Martins' trail, having had to fend off persistent rumours the former Inter Milan player could be on his way last summer after it was revealed he had a £13million get-out clause in his contract.
He said: 'We have had no contact with Villa or City about Obafemi Martins, but I can tell them - and anybody else, for that matter - that he is not for sale.
'In any case, I don't know how anybody can be expected to sign Martins when he is away in the African Nations Cup until the start of next month.
'It gets back to speculation again, which is one of the biggest distractions of the January window.
'Not only is it speculation about what you are bringing in, but unrest can be caused to your players who people are speculating might go out.
'Even though there might be no truth in it, that player might think I don't want him any more and am trying to sell him, and that can be very disruptive.
'That's why this window is a very dangerous one indeed.'
Allardyce, who revealed there has been no progress in the club's attempts to bring in defender Wes Brown from Saturday's opponents Manchester United, has confirmed his interest in Arsenal midfielder Lassana Diarra.
He said: 'If it's a possibility, we would always consider somebody who has good Premier League experience who we think would be a good addition to our team.'
Allardyce and chairman Chris Mort are working tirelessly behind the scenes to add new recruits to a squad which has lost four senior professionals to the African Nations Cup.
'When the window opens everybody expects there to be a mad rush,' said the manager.
'It seems to have given an expectancy to the whole of the fans in this country that there is always going to be massive amounts of money spent at every single window now.
'The bottom line is there are fewer players than ever before of the right ilk and the right quality worldwide available for football clubs to buy in this window in only four weeks.
'We are competing in that window with either other Premier League clubs or other clubs from abroad if it is a foreign player.
'Hopefully we can be successful as quickly as possible because my need is not in two weeks' time, my need is now to try to boost the squad.
'Even if we could pull one off before Manchester United it would give us an extra body to take into that game and beyond in this period when we have players either away or not available.'