After reaching the final on both of his previous appearances in this competition, Littler has yet to advance beyond the semi-finals this season.
He sits sixth in the table, level on points with defending champion Luke Humphries, and already a step behind the early frontrunners.
His scoring remains robust, averaging around 100 with a first nine-figure among the strongest in the field, but the concern lies on the outer ring.
Littler vulnerable?
A checkout rate in the low 30 per cent range represents a marked regression on last season's televised standards and has repeatedly cost him momentum in the race to six format, where one missed dart can flip an entire match.
He opens against table leader Jonny Clayton, who dismantled him 6-1 in Glasgow while averaging north of 104 and sealing victory with a 156 checkout.
Clayton's efficiency has been the benchmark across the opening weeks, and another clinical display would further expose Littler's current vulnerability under pressure.
Elsewhere, Humphries faces Stephen Bunting, still without a point despite posting competitive averages, while Michael van Gerwen returns from illness just one point off top spot. He meets Gerwyn Price in a repeat of the Night Two final.
Rock's star status
Local focus inevitably falls on Josh Rock, who is still searching for his first Premier League win after three quarter-final exits.
The numbers suggest he is closer than his record indicates. Rock is averaging in the high 90s and producing a first nine average comfortably above 100, placing him competitively within the field's scoring bracket.
However, his checkout percentage has trailed the tournament mean, sitting in the mid-30 per cent range, and he has missed darts to extend matches in each of his defeats.
Against Gian van Veen, who has already reached two nightly finals and sits third in the standings, Rock will need sharper efficiency at key moments.
The Belfast crowd may provide lift, but in this format, focus outweighs sentiment.