Swindon Town warned Celtic they will have to double their offer to land prolific striker Simon Cox.
Sportsmail understands that the Parkhead club approached the League One side with a package worth around £1.2million for Cox, plus teenage central defender Sean Morrison.
With a raft of English Premier and Championship clubs also interested in 36-goal striker Cox, however, Swindon rejected the proposal before slapping a £2.5m price-tag on the pair.
Chairman Andrew Fitton believes Champions League football would be a fitting stage for 22-year-old Cox, in particular.
Wanted: Celtic are keen to land Swindon's prolific striker Simon Cox but have been told to double their bid if they are serious
Adamant that he is in no rush to sell a player he signed for just £200,000 from Reading last summer, however, Fitton said: 'We value Simon at £2.5m. We have made no secret of what we think his value is.
'I'm not surprised Celtic's interest is not going away because Simon is a class player. We have had two approaches from clubs, but nothing in writing.'
More...Celts hit the wall: Caldwell blames negative Hibs for costly title slip
Kit parade: Celtic join Toon, City, Chelsea, Liverpool, United and Arsenal
CELTIC FC NEWS FROM ACROSS THE WEB
Celtic have yet to declare their hand on the future of Jan Vennegoor of Hesselink, with PSV interested in taking the Dutchman back to his homeland, but interest in Cox suggests there will be places up for grabs irrespective of this weekend's SPL climax.
'There is interest from one club in England. But what they cannot offer the player, unlike Celtic, is European football and playing in front of crowds of 60,000,' said Fitton.
Celtic have also enquired over 19-year-old defender Morrison.
Swindon recently had a bid of around £80,000 for Celtic defender Scott Cuthbert - who is on loan at St Mirren - rejected and a swap deal for the duo remains an option.
Another Parkhead loan star Paul McGowan, meanwhile, has warned Hamilton teammate James McCarthy to think carefully before holding out for a move to his boyhood idols.
Target man: Hamilton rejected Celtic's bid for rising star James McCarthy
Celtic bid £500,000 for the Hamilton prospect last week and are expected to return with an increased offer after manager Gordon Strachan confirmed his interest in the player.
McGowan fears McCarthy could struggle for first-team football at Parkhead, saying: 'James is young and needs to be playing football. It certainly wouldn't be a bad thing if he stayed at Hamilton.
'I'm sure he is good enough to make it at Celtic but it can be difficult - you just have to look at what happened to Derek Riordan.'
Meanwhile, Celtic coach Neil Lennon assured worried fans last night that Scott Brown should be okay for Sunday's vital home clash with Hearts - and allayed fears that he may need surgery.
The Scotland midfielder has been struggling with an ankle injury and was substituted in the closing stages of the 0-0 draw against Hibernian at Easter Road.
But Lennon told Celtic TV: 'Scott should be ready for the weekend, but he won't do a lot this week.
'He has had an ongoing ankle problem, but he had been getting through okay, although he struggled a bit in the last 20 minutes against HIbs.
'Hopefully, after a week's rest he should be OK. I wouldn't have thought it would go as far as an operation.'
http://www.dailymail.co.uk/sport/football/article-1184354/Celtic-told-double-bid-land-Swindon-striker-Simon-Cox.html?ITO=1490