The South African midfielder entered the fray as a half-time substitute for Ryan Jack with the Premiership leaders already 4-0 up against Hamilton Accies at Ibrox back on November 8.
Zungu duly cruised through the second half as Rangers racked up an 8-0 win, his contribution earning praise from manager Steven Gerrard.
Fast forward to the next meeting of the teams at Hamilton and Zungu can now be in no doubt as to the size of the challenge he faces if he hopes to turn his loan move from French club Amiens into a permanent deal this summer.
Handed his first Premiership start for Rangers, Sunday’s game in South Lanarkshire offered the 28-year-old the chance to stake his claim for more regular game time in the remaining three months of this season.
It was an opportunity Zungu was unable to seize with any conviction, his inclusion in the side clearly among those which an unhappy Gerrard admitted afterwards had given him cause for reflection.
Zungu was substituted on the hour mark, replaced by Jack as Gerrard sought to rebalance a midfield unit which was being outmuscled and outplayed by bottom of the table Accies.
It would be harsh to judge any player on one ineffectual display. Zungu has impressed in several of his previous outings from the subs’ bench and will be assessed by Gerrard and his coaching staff on a much wider body of evidence.
But as Gerrard continues to assemble a squad with both the strength and depth required to maintain Rangers’ current upward trajectory into a bid for Champions League group stage football next season, he needs to have greater certainty in Zungu’s reliability as an alternate for midfield mainstays such as Jack, Steven Davis and Glen Kamara.
With pre-contract signing Nnamdi Ofoborh joining Rangers from Bournemouth in June, there will be even greater competition for places in that department of Gerrard’s squad.
It leaves Zungu with limited time to ensure Rangers take up their option, believed to be priced at around £2.5 million, to trigger his permanent transfer from Amiens.
So far, he has started only four games in total for Rangers. Two of them were in the League Cup, including the shock 3-2 defeat at St Mirren in the quarter-finals, with one in the Europa League group stage away to Lech Poznan when Gerrard’s men had already sealed their place in the last 32.
Zungu did not complete the full 90 minutes in any of those four starts, making a further 12 appearances from the bench. While he has proved adept at coming on to help Rangers see out several victories from winning positions, Zungu has yet to indicate he can stamp his authority on a contest from the start.
Speaking to Rangers TV after Sunday’s fortunate 1-1 draw at Hamilton, Gerrard stated he would be “telling some individuals some home truths” this week as he picks through the bones of his team’s worst display of the season.
It’s unlikely Zungu will retain his starting place against Kilmarnock at Ibrox on Saturday. Time is now his enemy as he tries to secure a longer term future with Rangers.