Joe Royle admits that of all the players that left the Club in the summer, John McGreal's exit was the hardest to take.
The 32-year-old defender, who made 150 appearances for Town, returns to Portman Road at the weekend for the first time since his move to Burnley in July.
McGreal, out of contract with the Blues in the summer, signed a three year deal at Turf Moor and has helped transform Steve Cotterill's side into one of most difficult to beat in the Championship.
"I am not surprised that John has done well at Burnley because he's a good player," Joe told the Club website.
McGreal - left in the summer
"I never wanted to lose him and of the eight players that left the Club in the summer he was my biggest regret.
"With Jason De Vos coming in and Richard Naylor here as well, we had options at the back to play two or perhaps all three of them and I felt they would give us a basis to build on for this season.
"It didn't work out with John leaving and that was a blow to me."
