The Portugese have suffered once again from their dependence on Cristiano Ronaldo, with Nani their only other scorer this tournament. After a brace against table-toppers Hungary however, the current Ballon d'or holder may have found form at a crucial time.
Unlikely last-16 clash in Lens
The two teams saw their respective groups conclude in the most dramatic fashion.
In Group D, a late Ivan Perišić deflected goal against Spain in Bordeaux, saw Vatreni top the group. Whilst that saw the Spaniards finish second and the misfortune of facing Italy on Monday, Portugal's apparent settling for a point in the 3-3 thriller versus The Mighty Magyars in Group F, backfired spectacularly.
With the proposition of facing England once more in a major tournament, a stoppage time goal from Iceland's Arnor Ingvi Traustason on the break - as Austria pushed a for a late winner at Stade de France - suddenly saw Croatia ushered into Portuguese boss Fernando Santos' future. An altogether different task.
The clash, whilst unlikely, is set up to be a fascinating battle, as two of the more attacking units in the European Championships.
Seleçao must thwart dark horses
As many a dark horse have fallen by the wayside already in the stead of the plucky, Croatia stand tall as a significant threat that could challenge the European status quo.
Ante Čačić has guided his men through a tricky qualifying pool with flying colours. Having toppled the reigning champions as documented, The Blazers will be in bullish mood as they attempt to both quell the threat of Ronaldo and spearhead an attacking assault on Portuguesa Seleçao's defensively leaky unit.
With Luka Modric having missed out versus his domestic Spanish clubmates, it was instead Perišić who ran the show versus La Roja.
The Inter Milan man has been a shining light in France thus far this summer. The attacking winger's speed, guile and intelligence has been the driving force for the Croats, providing width, pace and creativity in droves. It is likely that Vieirinha will be tasked of shackling the 27 year-old, that will be key if Portugal are to progress.
Croatia have totalled one more goal than their opponents in the group stages with five. With both sides having shirked a defensive approach, a open and wildly entertaining encounter on Saturday evening in the north of France. Both sides have been wasteful of chances and it is likely the team of the greaters clinicians, will progress.
Could there also be a unlikely hero in the shape of Marcelo Brozovic for Croatia or Andre Gomes for Portugal?
For Croatia, midfielder Luka Modric could return after missing the win against Spain with a groin problem.
All of Portugal's players trained on Friday and coach Fernando Santos has a full-strength squad to pick from.
Left-back Raphael Guerreiro has recovered from the muscle problem that ruled him out against Hungary.