Sometimes, you get what you pay for. And it is clear to see even from his first few outings in the green and white hoops, that Celtic’s record signing Arne Engels is a quality footballer.

His obvious technical attributes and striking physicality aside, what has perhaps impressed the most to date is the temperament that has seen him coast through a debut against Rangers, make light of a high pressure penalty against Hearts, and tuck away another from the spot as he made his Champions League debut against Slovan Bratislava at a rocking Celtic Park.

The Belgian only turned 21 a couple of weeks ago, but the way he cruised through the game on Wednesday in particular even struck his teammates, like fellow goalscorer on the night, Liam Scales.

The defender has been blown away by the way Engels has handled the transition from Augsburg to Celtic, taking the £11m transfer fee the club paid for him and anything their opponents have tried to do to stop him in his lengthy stride.

He can play, but he can mix it too, as the rather heavy-handed Slovan midfielders found out during the week, and there is excitement within the Celtic dressing room around the new dimension that Engels may be able to bring to Brendan Rodgers’ team, particularly on the European stage.

“What’s that saying? If he was any more laid back, he'd be horizontal,” Scales said.

“Honestly, he's brilliant. It takes a lot of guts to come in and play the way he's playing, straight into these massive fixtures.

“Playing against Rangers, coming into the Champions League game and doing so well. He's got so much quality. I think everyone can see that. He's brilliant.

“I think he deserves that record fee. He's a top, top quality player. He's just been brilliant. He's really getting to know the lads as well. He's just been top class all round. I'm looking forward to playing with him.

“He's well capable of that other side of the game as well. Obviously, he's technically brilliant. You can see that, but I think that sort of goes under the radar of how good he is. He's just a bit of a machine.

“There are players bouncing off him and he's really getting into tackles. It's great to see that. You need your midfielders to do that.”

Another aspect of Engels’ game that has been notable has been his set-piece delivery, something Scales took full advantage of to crash home the opening goal of Celtic’s Champions League campaign.

“I watched it back and the player a yard in front of me is at full stretch, in the air, and it's gone over his head and come down just in time to be right on my head,” he said.

“I've not even really had to jump. You can't really defend against crosses like that if it's got so much whip and dip on it.

“Obviously, we're at an advantage that we know what area he's going to play it into and I'm going to make my run into there. It was perfect.

“I didn't have much to do other than just get good contact on it.”

If Scales was keen to downplay his own role in that goal, he was certainly up for making the most of the celebration that followed, with the explosion of noise from the Celtic Park stands a memory he will carry with him for the rest of his days.

“It was just pure joy,” he said.

“You could probably see that on my face. I wanted to do a knee slide, but someone pushed me over! It was just pure joy. I was delighted and it was such an amazing feeling.

Read more:

“Obviously getting the result is the main thing but to get a goal in the Champions League is something I'll have now forever.

“It was just such a great start to the competition. In the first half we were a little bit tentative, but we played our way into the game. The second half we came out and blew them away. So that was brilliant.

“What we wanted was three points and we got that and the performance and the scoreline were brilliant as well, so we’re delighted.

“We [put down a marker], 100 percent. Obviously, you feel the atmosphere here. The teams coming here are going to feel that. It is important for us to pick up as many points at home as we can.

“It's a perfect start really. You never know. It might come down to goal difference so to get five goals is brilliant as well.”

For all the euphoria around Celtic Park and the deserved plaudits the players are enjoying, Scales knows though that tougher tests lie ahead, and no more so than in their next two Champions League fixtures when the team travel to take on last season’s finalists Borussia Dortmund before heading to Bergamo to face Europa League champions Atalanta.

With three points in the bag and more favourable-looking home games to come, some may view those matches as something of a free hit for Celtic, but that’s not how Scales sees it.

“It's the best start we could have hoped for,” he said.

“Now, can we build on it? We have to use it as a platform to continue to get good results.

“I think we're in a really good place at the moment. We're probably in the best place we can be to go and do well this year in the Champions League. That's the hope. We need to take it game by game and focus on picking up results.

“Even against the top-seed teams. We need a bit of belief. If we play our game and play well, we can do it.

“[Dortmund and Atalanta] will be, on paper, probably the toughest ties that we have. Some people might say it's a free punch, but for us it's not.

“We want to go and approach every game the same way. We're seeing them as games that we can potentially win. That's how we prepare for them.”