Old Firm rivals Rangers bettered Dundee across the road at the Kilmac Stadium, Dens Park yesterday to take their place in the hat – and either Celtic or the Tangerines will join them at Hampden, alongside both Hearts and Hibs who also qualified earlier in the weekend.
With a rare week-long preparation for the game, Ange Postecoglou had refused to give his squad too much time off, and instead pledged to freshen them up at the training base in Lennoxtown ahead of the game which is also followed by another five-day wait before returning to league duty at home to Ross County.
As such, with a well-rested pool to choose from, there are several positions to consider, especially after the win against Livingston saw a timely boost for Daizen Maeda and a goal for James Forrest.
Anthony Ralston also featured in west Lothian an the Scottish full-back could be in a strong position to retain his place against his former club and keep Josip Juranovic out with some key league fixtures including an Old Firm game on the SPFL horizon.
David Turnbull is edging closer to more involvement but a game like this is likely too soon, and too important, after the midfielder’s near three-month absence with Reo Hatate able to continue alongside Callum McGregor. Likewise Christopher Jullien could have designs on a place in the team, but may have to wait to dislodge either Carl Starfelt or Cameron Carter-Vickers.
In attack, Giorgos Giakoumakis has scored in each of the previous rounds and despite Maeda’s goal at Livingston, he’ll likely be asked to do the same against United. Whether or not Jota, Liel Abada or James Forrest will be laying the opportunities for him though is one of the key questions facing Ange Postecoglou on the road to Tayside.
Here's how Celtic could line up at Tannadice this evening…
Celtic: Hart, Ralston, Starfelt, Carter-Vickers, Taylor, McGregor, Hatate, Rogic, Forrest, Giakoumakis, Jota.