Ronny Deila says he will not apply restrictions to his players' social lives simply because Lukasz Zaluska, the goalkeeper, was attacked and knocked unconscious in Glasgow at the weekend.

Zaluska was allegedly punched by two rival footballers in an assault during a night out in the city's west end. The incident happened in the early hours and is now being investigated by police. Deila's predecessor, Neil Lennon, was assaulted in the same street, Ashton Lane, six years ago.

Deila spoke with Zaluska, who was out cold for three or four minutes after being hit, and was confident that his back-up goalkeeper was physically and mentally okay. He said the 32-year-old Pole was blameless and therefore there was no reason to apply any code of conduct on his ­players because of an isolated incident. Zaluska had been out with his wife and a female friend.

"It is not a problem if they want to go out for dinner and do something social," said the manager on the eve of tonight's home Europa League group game against Astra Giurgiu of Romania. "Of course that is okay. He hasn't done anything wrong. He was out for dinner and that is perfectly right. That's why you get frightened about this, it's not fun to experience things like that and we have to take care of him. Hopefully, the case will come right.

"He is fine. Of course he was a bit scared about this but everything is good now. He has trained well the last couple of days so is ready for tomorrow. I talked to him of course, about what happened. It is a police case now. He hasn't done anything wrong from our perspective. We just have to support him and of course feel sorry for him because that is a hard thing to go through."

A witness has said Zaluska was punched twice by one rival player, on the side of the head and then in the face, before a second player ran up and hit him on the head. It is believed he was knocked unconscious when his head struck the pavement after being hit by the second player.

Deila was asked if Zaluska had feared things could have been worse: "In his brain I think there is no ­problem. He is training very well and seems comfortable."

Deila felt there was no need to apply any new disciplinary measures or restrictions on his players because of what happened, despite the obvious attention Celtic players attract when they socialise in Glasgow. "I have other people with experience [of Glasgow] in my [coaching] team. If this was happening a lot of times I would have to do something of course but I think this is a one-time situation, hopefully. You learn by experiences. You have to understand the life that you have in that city. They are role models and that is important to think about .

"Like I said before, Glasgow has been different, of course, to what I am used to. But I think people are very polite and very positive. Going out for dinner isn't a problem. Some people want a picture or things like that but that's just what you have to do when you have this job. You meet supporters and people interested in football. That's fine."