Pochettino goes to Old Trafford for his second game in charge.
And Manchester United chief Fergie described Saints chairman Nicola Cortese, who axed Nigel Adkins, as a "work of art."
He said of Argentine Pochettino: "I don't know a lot about him to be honest.
"Nigel spoke to me the day before he was sacked. You cannot understand these things.
"Their form had picked up, two defeats in 12 games. I have to be careful what I say about their chairman but apparently he's a work of art."