Celtic have been warned not to make a second bid for Burnley striker Kyle Lafferty.

The Northern Ireland striker was the subject of an offer from Parkhead, reported to be £500,000, which Burnley instantly rejected.

The Coca-Cola Championship side are determined to keep Lafferty at Turf Moor and insist they will not entertain a further approach from Celtic for the 19-year-old.

Manager Steve Cotterill, who insists Lafferty is worth at least £6million, said: "The bid that has been made for Kyle is nowhere near acceptable.

"With those words we are not encouraging anyone to come back with a bigger bid because he is not for sale."