Neil Lennon hailed Jeremie Frimpong as an "outstanding talent" after the 19-year-old turned in another fine performance in Celtic's 2-0 win over Hibernian on Sunday.
The Dutch defender was not registered in the Hoops' Europa League squad after signing from Manchester City in September for a fee reported to be around £350,000 with potential add-ons.
However, right-back Frimpong quickly forced his way into the first team for domestic games and, after missing out on the Europa League dead rubber against Cluj on Thursday night, returned to score his first home goal against Hibs.
The results saw the champions move two points clear of Rangers at the top of the Ladbrokes Premiership, with French striker Odsonne Edouard scoring the second.
The Parkhead boss described Frimpong as "one of the best kids I've ever seen at that age", then added: "I'm not going to big him up, that's not my role as a manager.
"I'm just delighted what he brings to the game, defensively or offensively and there is as an end product as well.
"He put a couple of chances on a plate which we should have benefited from.
"He's an outstanding talent who looks after himself. Watching him makes me tired, the amount of runs he makes, he wears people down.
"He is an amazing player. Amazing. With younger players you want to look after them but you can't hold talent back.
"We looked at him in training two or three months ago saying, 'we have to get him in the team', he was that good.
"The big question is can he transmit all that on to the playing field. He's done that incredibly well.
"He's playing with some good players too, he will be first to admit that, but from what he brings to the team, he's been outstanding."