The Tangerines, who have undersoil heating, arranged an unexpected pitch inspection for 12 noon and then a subsequent one at 1.30pm.
The fact that an inspection was needed in the first place has “disappointed” Saints, as has the timing of the call-off.
The match has been rearranged for 6.30pm on Tuesday night.
A statement from the Perth club read: “We are disappointed the game was called off just over 90 minutes from kick-off.
“With Dundee United having undersoil heating, we fully expected the fixture to go ahead. We did not expect this.
“We now fully expect the SPFL to look into why the game could not be played and why it was such a late call off.
“Callum (Davidson) and the players prepared for this game and we feel for them not to have the game on.
“Thankfully, with supporters not being allowed into games, none of our fans had travelled to Tannadice.
“So, that’s an upside. It was also the day that Dundee United paid their tributes to Jim McLean after his sad passing.
“All in all, it’s been far from ideal.”