Dundee United manager Peter Houston has apologised to Hibernian fans for allowing new signing Rudi Skacel to choose shirt number 51.
The Czech winger opted for the digits as a tribute to former club Hearts' 5-1 win over Edinburgh rivals Hibs in the William Hill Scottish Cup final.
Former Saints midfielder Skacel had been training with his old club - who are now under a transfer embargo until Christmas - before penning a short-term deal with United yesterday.
Houston claims he had no idea of the significance of the squad number until it was too late.
Speaking after a 1-0 win over St Mirren in the Clydesdale Bank Premier League, he said: ''It's not my style to upset people.
''I said there were a few numbers available and he asked for 51.
''Call me naive but Gary Hooper wears 88 and Victor Wanyama wears 67 and I never thought of 51 being 5-1. Trust me, when I say that.
''It's registered straight away and, once you register it, you can't go back on it.
''I apologise to the Hibs fans. If I'd known, I wouldn't have given him the number.
''I'm not in the habit of trying to wind people up or noise other clubs up. Hibs are a fantastic club.
''Last night I was at Fir Park at Motherwell's game against Hibs doing TV and there were boys running down the aisles trying to have a go at me.
''I spoke to a couple of them and they were very reasonable.
''But I wouldn't have given Rudi the 51 if I'd thought about it clearly. It wasn't until the next day that someone mentioned it to me.''
Skacel came off the bench for the final 25 minutes in Paisley, with a Johnny Russell penalty in the second half securing the narrow win.
Houston added: ''We've got Rudi until the end of January. I'm sure he's a player we'd like to keep.
''He was brilliant in negotiations, he's on nowhere near the kind of money he was probably on at Hearts.
''All he wants to do is play. Where I've got it wrong, is letting him pick the 51 without switching on to it.''
The 1-0 victory ended a winless streak in the SPL for United and Houston hopes the result can act as a springboard.
He said: ''After not winning the last six games, it was important that we got the three points, rather than playing well and just getting a point.
''We've still got two games in hand so this game could kick-start our season.
''We ground out a result without being brilliant today. It was maybe tough on St Mirren but that's the way it goes sometimes.''
Saints boss Danny Lennon wanted a reaction from his players after last week's 5-0 thrashing at the hands of Celtic.
He said: ''I was disappointed not to take a single point from the game.
''The character was suspect last week and they certainly answered that today.
''We had a lot of possession. The operation went well but the patient died.''