Victor Wanyama, Beerschot, £900k

Was courted by major European clubs but Celtic were the ones to take a £900,000 chance on the midfielder from the Belgian side Beerschot. Physically and technically a highly impressive player, the 21-year-old Kenyan has now been linked with both Manchester clubs and rated at £25m by the Parkhead manager

Emilio Izaguirre, Motagua, £600k

Injured for Barcelona's visit, with fitness troubles halting what had been previously stunning progress for the left-back in Glasgow. Celtic stepped in ahead of Seattle Sounders to lure Izaguirre, 26, from his home country, Honduras, after he impressed at the 2010 World Cup

Fraser Forster, Newcastle United, £2m

Signed for Newcastle's academy in 2005 and was contracted to the club until last summer, when Celtic made two earlier season-long loan deals into a permanent one. The 6ft 7in goalkeeper's form, especially in European ties, has prompted a call-up to the past two England squads

Tony Watt, Airdrie United, £50k

The scorer of Celtic's second goal against Barcelona played only 15 first team games for Airdrie United before Celtic signed him for £50,000. At 18, he is one of Scotland's brightest prospects. In just 11 appearances for Celtic, Watt has scored six goals

Adam Matthews, Cardiff City, free transfer

The energetic 20-year-old defender is comfortable on either flank, as demonstrated when he was switched to left-back and excelled during Barcelona's visit. Enjoyed a stunning start to his career in Glasgow after arriving on a free transfer from Cardiff City but had faded slightly before a terrific display in the Champions League victory

Gary Hooper, Scunthorpe United, £2.4m

Celtic's top scorer has also attracted the attention of Roy Hodgson, who would have called the 24-year‑old into his squad for next week's friendly in Sweden but for injury. Hooper was at Grays Athletic six years ago and arrived at Celtic via Scunthorpe United. Liverpool are rumoured to have tabled a £9m bid for the striker