Some viewers complained to the channel following the decision, but ITV can hardly be criticised for this one. The game at St Mary's is one of only three or four that stand out in the draw.
However, more discerning viewers may be asking themselves: when were Manchester United not on live television in the FA Cup?
And the answer is really a quite amazing one. Every game featuring United in the competition has been featured live since their 0-0 draw with Exeter in January 2005.
That will be 30 games and counting, including the Southampton match.
Up for the cup: Ryan Giggs celebrates with team-mate Javier Hernandez after scoring United's third round winner against Liverpool last weekend
Perhaps you can't blame the television companies in a way - United are said to add a million television viewers when their games are screened. This might explain why ITV often choose to show their Champions League matches live on a night when other English teams are playing.
In saying that, a quick look at the list of games over the last six years shows that at times there has been a complete lack of imagination.
Why for example did the BBC show United's third round replay with Burton at Old Trafford in 2006, a game which was barely a contest as the hosts cantered to a 5-0 win?
Heads up: Giuseppe Rossi scores for Manchester United against Burton at Old Trafford in 2006
And United's home matches against Portsmouth and Reading in 2007 were hardly ties to set the pulse racing, but the BBC selected them for Saturday night television.
Maybe supporters of United's rivals shouldn't be complaining too much though. There is one common theme since this live television run began in 2005.
Despite reaching two finals and one semi-final in that time, Sir Alex Ferguson and United haven't managed to win the old pot.
ARE YOU TIRED OF SEEING MANCHESTER UNITED ON THE BOX? OR ARE THEY SIMPLY THE GAME'S BIGGEST DRAW? HAVE YOUR SAY BELOW
United's live television matches in the FA Cup:2005:
Third Round replay: Exeter (away) BBCFourth Round: Middlesbrough (home) BBCFifth Round: Everton (away) BBCSixth Round: Southampton (away) BBCSemi-final: Newcastle BBCFinal: Arsenal BBC
Third round: Burton (away) SkyThird Round replay: Burton (home) BBCFourth Round: Wolves (away) SkyFifth Round: Liverpool (away) BBC
Third Round: Aston Villa (home) BBCFourth Round: Portsmouth (home) BBCFifth Round: Reading (home) BBCFifth Round replay: Reading (away) BBCSixth Round: Middlesbrough (away) BBCSixth Round replay: Middlesbrough (home) SkySemi-final: Watford BBCFinal: Chelsea BBC
Third Round: Aston Villa (away) BBCFourth Round: Tottenham Hotspur (home) BBCFifth Round: Arsenal (home) BBCSixth Round: Portsmouth (home) Sky
Third Round: Southampton (away) SetantaFourth Round: Tottenham (home) ITVFifth Round: Derby (away) ITVSixth Round: Fulham (away) ITVSemi-final: Everton ITV
Third Round: Leeds (home) ITV
Third Round: Liverpool (home) ITVFourth Round: Southampton (away) ITV
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