Jim Goodwin has revealed his "biggest mistake" at Celtic as a player came when he offered to play right-back on his debut.
The Dundee United boss made his only appearance for Celtic under Kenny Dalglish back in 2000.
Goodwin - who previously managed Aberdeen, St Mirren and Alloa - has revealed he offered to fill in at full-back on his debut as he allowed John Kennedy to play in central defence.
The League Cup winner was in line to play centrally himself in the match against Dundee United but offered to switch role with Kennedy to assist his team-mate.
However, Goodwin reckons his attempt to show a "good attitude" came back to "bite him on the a***" as Kennedy went on to play further matches for Celtic and transition into a coaching role at the club following his playing career.
Discussing his debut on Open Goal, Goodwin commented: "When John Barnes got the sack then Kenny Dalglish and Tommy [Burns] had taken over just on a caretaker role.
"And listen, they were giving out debuts like packets of crisps at that time.
"Guys like myself and one or two others were given that chance in the last game of the season."
And on his position switch offer that backfired, Goodwin explained: "I started the game and one of the mistakes I made in the build-up to that game that I haven't actually spoke about a great deal but we were shaping up and John Kennedy was supposed to play right back.
"I don't know if he will remember it but he was like a duck out of water playing at right back and I was playing at right centre-half which was my position coming through the system.
"And I had offered to play right back instead because Kendo didn't want to do it and I thought, 'I don't mind playing there'.
"That was probably my biggest mistake. He was brilliant at centre-half and I was bang average at centre-half! I went off with cramp after about 75 minutes because I was running up and down the line and I wasn't used to doing that!"
The Dundee United boss joked: "Listen, I would never have been the Celtic centre-half for 20 years! I said to Tommy, I said, 'If he doesn't want to play there I don't mind playing there'.
"I thought I was doing a good thing and showing a good attitude to the manager but it came back to bite me on the a*** because Kendo went on to play a hell of a lot of games at centre-half!"
