Virgil van Dijk claims he knows nothing of interest from English clubs and is keen to prove himself in the Champions League with Celtic.
QPR loanee Tom Carroll wants to "make it at Tottenham" but is prepared to consider all of his options at the end of the season.
The 21-year-old stopper is yet to make a first-team appearance for the reigning European champions but has made more than 60 Football League appearances during loan spells with Barnet, Yeovil, Bristol Rovers and Northampton.
Walker's arrival at the Weston Homes Community Stadium seems to suggest manager Joe Dunne will remain in his position, for the time being at least.
Dunne admitted he was considering his future after Saturday's 2-1 home reverse at the hands of fellow strugglers Scunthorpe - a ninth successive league defeat and an unwanted new club record.
Dunne is also close to bringing in another unnamed player, believed to be former loan striker Jabo Ibehre.