The visitors enter this year's competition in this round while the hosts navigated through the group stage to reach the knockouts.
Match preview
Dundee United return to action on Sunday aiming to continue their Scottish League Cup run, having successfully progressed through the group stage in July.
That is despite a losing start at the hands of Falkirk, as Jim Goodwin's side bounced back in style in their remaining three games, beating Stenhousemuir, Ayr United and Buckie Thistle 3-0, 2-1 and 5-2 respectively to take second spot and qualify as one of the best runners-up, having pipped Livingston to the final spot on goal difference.
Since that cup success, the Tangerines have kicked off their return to the Scottish Premiership after winning the second tier last time around, beginning with a 2-2 draw at home to rivals Dundee having twice gone ahead through Kristijan Trapanovski and Miller Thomson.
A trip to Ross County then followed on Saturday, and Goodwin's men looked set to put their first league win on the board having led 1-0 through David Babunski heading into injury time, only for Ronan Hale to draw the visitors level in the 95th minute.
While left disappointed having been pegged back in their first two Premiership outings, Dundee United certainly have positives to take from their displays in both contests and their Scottish League Cup group campaign, and they will bid to build on that with a fourth straight cup win on Sunday to book their place in the quarter-finals.
Their visitors, meanwhile, head into their first League Cup action of the season having earned a bye through the group stage thanks to their place in continental qualifying.
Following a fifth-placed finish in the Scottish Premiership last time around, alongside a quarter-final exit from the Scottish League Cup at the hands of Hibernian, St Mirren entered qualifying for the Europa Conference League qualifying in the second round and successfully moved within two ties of the league phase with a 4-1 aggregate triumph.
The Saints' league campaign then kicked off in a mixed manner in early August, initially beginning with a 3-0 beating of Hibernian, only to travel to Aberdeen last weekend and succumb to a 3-1 defeat after a 1-1 draw in the first leg of their third-qualifying-round tie with Norwegian outfit SK Brann on home turf.
Following that disappointing defeat last Sunday, Stephen Robinson's side most recently travelled north for the second leg of their continental qualifying tie on Thursday and fell just short, drawing level at a goal apiece on the night through Alex Iacovitti 16 minutes from time, only for Felix Myhre to restore the hosts' lead in the 85th minute before Aune Heggebo put the game out of sight.
Having now bowed out of European qualifying after a valiant effort, St Mirren will now bid to mark their return to domestic action with a victory to progress to another Scottish League Cup quarter-final before turning their focus back to the top flight next week.
Dundee United Scottish League Cup form:
L
W
W
W
Dundee United form (all competitions):
W
W
W
D
D
D
St Mirren form (all competitions):
D
W
W
D
L
L
Team News
Jim Goodwin should field a similar Dundee United starting XI from last weekend's 1-1 draw with Ross County, although Louis Moult should come in from the start up front, having settled for a substitute appearance in that game after notching up a team-high tally of 20 goals last season.
He will have support from winger Kristijan Trapanovski, who has already netted four goals in six appearances for the Tangerines following his summer arrival, while fellow new signing David Babunski has contributed three of his own from the midfield.
Babunski should line up in the engine room alongside mainstay Craig Sibbald, while Emmanuel Adegboyega, Declan Gallagher and Kevin Holt will continue in a back three.
St Mirren continue to deal with several injury issues heading into the weekend, with Greg Kiltie, Connor McMenamin and Mark O'Hara set to remain confined to the treatment room.
Stephen Robinson may opt to freshen up his starting XI after their midweek defeat to Brann, although Tolusi Olusanya should continue to lead their attack, with Jonah Ayuga also fighting to keep his place.
Mikael Mandron could also come in to bolster their attack, having netted a team-high tally of 11 goals last season, while Alex Iacovitti is in line to come into the defence from the outset having largely featured off the bench since his summer arrival from Port Vale, including scoring their leveller on Thursday.
Dundee United possible starting lineup:
Walton; Adegboyega, Gallagher, Holt; Sevelj, Sibbald, Babunski, Ferry; Trapanovski, Moult, Thomson
St Mirren possible starting lineup:
Balcombe; Idowu, Iacovitti, Taylor, Brown; Fraser, Gogic, Smyth; Mandron, Olusanya, Ayunga
We say: Dundee United 2-1 St Mirren
We anticipate a tight contest on Sunday between two sides with similar quality at Tannadice Park.