Peterborough United boss Darren Ferguson has confessed that allowing full-back Russell Martin to leave the club for Norwich City remains his biggest regret as a manager.

Scotland international Martin and fellow defender Ryan Bennett are the two ex-Posh players set to face their old club at London Road in this afternoon's pre-season friendly.

Martin was captain when Peterborough won promotion to the Championship under Ferguson in 2009 in his first spell in charge, but six months later, he joined the Canaries on loan and was allowed to make the move permanent in January 2010.

He has since played a part in City's back-to-back promotions and a mid-table finish in the Premier League, and has picked up three international caps.

'It will be great to welcome Russ and Ryan back to London Road. Letting Russ go is my biggest regret in management. He was an outstanding captain for us when we won promotion to the Championship the first time and one of the most consistent players in the team,' said Ferguson.

'We didn't start the following season very well, but I should have stuck with Russ rather than letting him go on loan to Norwich. It's worked out great for him though and I couldn't be happier for him because he is a top bloke as well as a very good player.'

Ferguson, now in his second stint with Posh after a disastrous spell as Preston manager, also wishes Bennett well after his move to Norwich for a reported �3.2m last season.

'It was fantastic to see Ryan playing in the Premier League last season and he deserved it as he was outstanding for us. We didn't want to lose him, but we couldn't deny him the opportunity to move on to such a good club,' he said.

'I love the way Norwich play football and to be honest I've tried to get us playing in a very similar way with mobile, fluent midfielders. Paul Lambert did a great job for them and I'm sure Chris Hughton will carry on the good work. It's a good test for us at this stage of the season and it's a game we are all looking forward to playing.'

Martin's last appearance for Posh at London Road was back in October 2009.

'It's my first time back. I've been back to watch one game since I left but I've not played there, so it will be good,' he said. 'Benno's a bit fresher than me there. I look forward to it. It's against my old manager there and I still know quite a few of the lads.'