IT may be best described as the conversion on the road to Dalmarnock.

Peter Grant, then the Celtic assistant manager, had firm views of Scott Brown in the spring of 2010. "If somebody had offered us £4m, I would have driven him down the road myself. Absolutely," he said yesterday of reports linking the midfielder with English clubs. "He wasn't playing well enough, he was ill-disciplined, doing things you can't do in that position. So I would have grabbed the fee with both hands."

And there is more. That spring was marked with two significant moments for Brown, who had cost the club £4.4m in 2007. First, he was given the captaincy by Tony Mowbray, much against the advice of Grant. "I said: 'What? He shouldn't even be playing in the team'. That's what I felt at the time. I didn't feel he should be a regular because he wasn't playing well enough," said the former midfielder.

"I think Peter Lawwell [Celtic chief executive] was wanting Robbie Keane to be the captain and, when Tony said that to me, I said: 'You can't give loan players the captaincy at Celtic Football Club. Gie's a break'. When he said Scott Brown, I said: 'Not for me, gaffer. He shouldn't even be playing'. I've been delighted that he's turned it around. This season and the end of last season, I'm so pleased to see how he's played in that position."

Grant's conversion is the more dramatic because he was also dismayed by another significant moment in Brown's career when the former Hibernian player was sent off after clashing with Kyle Lafferty in an Old Firm game in February, 2010. Celtic sacked Grant and Mowbray one month later and the former assistant manager was angry at Brown being dismissed with Rangers subsequently scoring the winning goal through Maurice Edu late in the game.

"One of the last words I had with him was at half-time in the Rangers game," recalls Grant, who played 362 games for the club in a Celtic career that stretched from 1982 to 1987.

"I said to him: 'Listen, I know what it's like. I've been there. I want to kick him [an opponent] up and down the pitch because of what he's done, because I've seen what he's done. But know that the ref is looking at you'.

"The referee used to say to me, in the tunnel before we went out: 'Peter, you're not even getting one today'. So I told Scott that I knew what he was going through, that he wanted to just say, 'Right, I'll show everybody how big I am'. I had to learn that as well."

Grant believed his message to his midfielder was being transmitted successfully. "He seemed to be taking the information in when I told him to keep calm. So, after the game, I'm spitting feathers. We lost the game in injury-time. And whether it was an ordering off or not, he put himself in the position. At that time, I thought he was never in a million years ready to become Celtic captain."

He believed Brown's motivation was misguided. "It was getting to the stage that he wanted to keep the fans happy, thinking: 'I'll show them; I'll get stuck in'. But that lasts so long. You've got to produce, got to play the right way. And that is happening now. Everything is snowballing. I?¯saw him playing against some of the best players in Europe when Scotland took on England, and he led his troops so well."

Grant, who has coached at Norwich City, West Ham United, Birmingham City, and Aston Villa, has an intimate knowledge of the English game and was convinced Brown could not play in the Barclays Premier League.

"I?¯remember people talking about Tottenham or other Premiership sides offering £4m for him. I was thinking: 'Who are they sending to watch the games?' That's not being disrespectful, it's just fact. I know the teams they were talking about, I'd been down there, and he wouldn't get anywhere near those teams. He wouldn't be in the 18 on a Saturday. You can't play the way he was playing and affect the games down there. No chance was it going to happen."

The conversion was made as Grant started to watch more Scottish games of late in his role as a media pundit.

"If he keeps doing what he's doing, he's one that Celtic might struggle to keep hold of. He's got all the energy; he's playing the position exceptionally well; he's gained experience; he's shown talent against big teams: that makes him an attractive prospect."

Grant believes that Brown, now 28, has matured but has also benefited from playing alongside Joe Ledley. The Scotland internationalist, he pointed out, had become more measured in his passing, more disciplined in his positioning and more appreciative of what is required of him in a midfield role that has defensive responsibilities.

Grant reflected on a match in Israel against Hapoel Tel Aviv when Celtic led but lost 2-1. "He gave the ball away for their goal. We were one up after 75 minutes, absolutely cruising, and it was stifling hot. Just sit, stay disciplined. For the second one, he's caught out of position because he's away running forward. We're away from home, we've told him what to do. Why [did he] not do it? Indiscipline."

Grant now has faith that the Scotland and Celtic captain can now achieve an enduring reputation in the game, saying: "Scott Brown, 100%, can get close to the standing of guys like Paul McStay and Roy Aitken. If you had asked me two years ago, I would have said absolutely not. But now? He's done exceptionally well; he's grown into the captaincy. He must be living right; he must be doing everything right because he seems a different type of player."

The once doubting Peter ends his litany of praise for the one-time sinner with a final benediction: "This is his time and he deserves all the credit he gets."

Peter Grant was helping the Scottish Football Association and Tesco Bank launch the fourth year of the Tesco Football Challenge which involves 61,112 pupils from 1562 primary school in Scotland participating in a healthy lifestyle.