Celtic manager Gordon Strachan could turn his attentions elsewhere after failing with a bid for Burnley's teenage striker Kyle Lafferty.
Lafferty, from Northern Ireland, stands 6ft 4in and is already a full international.
Celtic were keen to bring him to Parkhead, however their offer - reported to be £500,000 - fell well short of Burnley's asking valuation of the 19-year-old.
With Burnley rating Lafferty in the £6million bracket, Celtic may not return with a second offer unless they can be convinced there is room for negotiation with the Coca-Cola Championship club.
Strachan has other options, and has already declared his interest in bringing Geoff Horsfield to Glasgow from Sheffield United, where the 33-year-old is out of favour.
United boss Neil Warnock told the Sheffield Star: 'We will not be giving away Geoff for nothing, definitely not.'
But after hearing of Celtic's approach for Lafferty, Warnock's initial impression was that Horsfield would not be moving north of the border.
'I don't know what has changed their minds but if they've gone for the lad from Burnley then I can't see them going for Geoff as well,' said Warnock.
'I'm not totally sure but that's the way I read the situation.'
That may not be the case now, given Burnley's firm stance on Lafferty.
Clarets manager Steve Cotterill stated: 'Even if we were to sell Kyle, the offer Celtic made wouldn't even be close to our starting valuation for a player of Kyle's undoubted potential.'
Cotterill told the Daily Express: 'Look at David Nugent at Preston. They value him at around £6million. Kyle is two years younger and is a full international, so you would have to put the same value on him - if not more.'
Strachan was foiled earlier this month in another move for a striker when he failed to lure Anthony Stokes to Parkhead.
The youngster had impressed during a loan spell at Falkirk, but preferred to join Sunderland from Arsenal.