SAINTS ace Fraser Forster knows first-hand England can expect an atmosphere like no other when they walk out at a packed Celtic Park to face Scotland tomorrow night.

Forster, 26, spent four seasons at Celtic, moving north of the border permanently in July 2012 after loan spells from Newcastle.

The 6ft 7ins stopper could be in line for a rare international cap tomorrow, after manager Roy Hodgson allowed England number one Joe Hart to return to Manchester City following the Euro 2016 win over Slovenia at Wembley on Saturday.

Forster, who joined Saints in the summer for £10million and has only conceded five league goals in 11 games so far, would relish the chance to represent his county at a venue he called home for so long.

“It will be a fantastic atmosphere and to play in a Scotland-England game would be a dream come true," said Forster, who won the Scottish Premiership three times with Celtic, as well as the Scottish Cup twice.

"It is an unbelievable atmosphere. I have only sampled it at club level, but the Barcelona players came out after a Champions League match and said it was the best atmosphere they had ever played in.

“With the calibre of players they have got, who have played in some big games and to hear them come out and say it was the best, tells you how unique it is.

“Celtic Park is a fantastic stadium, it is quite tight, so it will be really loud and will make for a fantastic game.

“It will be good to go back. I have got fantastic memories of being there. I know a few of the lads on their team and it will be a special night."

Forster added: “We had a great team spirit at Celtic and a good group - they didn't used to pick on me as the Englishman, everyone just wanted each other to do well.

“I have some close friends in the group - Scott Brown, Charlie Mulgrew, Shaun Maloney - all top players.

“Scotland have had a great start to their qualifying campaign, but so have we. Both teams will be full of confidence and that will add to the occasion.”

It was a tough decision for Forster to leave The Bhoys in late August and look to further his career in the English top flight, but one which so far looks vindicated following Southampton's superb start.

“I had a great time at Celtic and will be forever grateful for what they did for me. They gave me a chance and really believed in me," he said.

“Celtic gave me the opportunity to play Champions League football and European football. It was something really special.

"It was just a case of in the summer I thought it was time to move on for a new challenge.

"We have had a great start, which is a real credit to the manager and everyone connected with Southampton.”

Hodgson has yet to confirm whether Forster or fellow deputy Ben Foster of West Brom will be between the posts on Tuesday, and indeed could decide to give both men a half each.

Forster, though, has no issues with playing understudy to the City stopper.

"Joe is a top-top keeper. Ben and I know that, we see him in training every day, but we have got a fantastic group," he said.

“We work really hard and bring the best out of each other. We all want to show what we can do.

“You have got to be focused and concentrate.

“You never know when there will be an injury or there is a sending off and you will be needed.”