Perhaps it was fatigue, with some players confirming their place at the tournament only within the last 48 hours, arriving in Singapore just in time to dab on some concealer and throw on a dress before yesterday's draw ceremony.
Or maybe the absence of three-time defending champion Serena Williams had something to do with it.
But one thing is for sure: The mood at Marina Bay Sands last night may have been slightly subdued compared to last year, but the BNP Paribas WTA Finals Singapore presented by SC Global starting tomorrow will be anything but.
The draw ceremony ensured some mouth-watering battles.
On paper, the Red Group, with top seed Simona Halep, Maria Sharapova, Agnieszka Radwanska and Flavia Pennetta drawn in it, seems the tougher of the two.
So much so that even an in-form Radwanska, who recently picked up two titles on the Asian swing, found herself hoping for a bye.
Said the clever and crafty player, aptly nicknamed "The Ninja": "I wish I had a bye, but there are no byes, so I have to stick with my group. There are obviously no easy matches."
Second seed Garbine Muguruza, who dazzled the crowd in a black toga much like how she captured the attention of the tennis world this year, was put into the White group.
The 22-year-old started the year ranked 24th, but went on to make the Wimbledon final and lift the China Open this month to find herself at a career-high ranking of No. 4 and the second seed on her WTA Finals debut.
She finds herself alone in a group of lefties, with Petra Kvitova, Angelique Kerber and Lucie Safarova all drawn in the same group.
Said the Spaniard: "It's weird, right? The matches are very tough here anyway.
"It's curious. I'm going to be playing the next couple of days only lefties. Three matches, three lefties. I have a lefty coach also."
The top two from each group - named after the colours of the Singapore flag - will advance to the semi-finals.
The race to qualify for this year's WTA Finals has already stood out as the tightest in the 43-year history of the crown jewel of the women's tennis Tour. If that is anything to go by, the prize come Nov 1 will be anyone's for the taking.
The 2015 edition of the prestigious US$7 million (S$9.75 million) season finale will feature debutantes in Safarova and Muguruza, but also in Pennetta, a first-timer playing the last Tour event of her professional career.
All of the "Elite Eight" are Europeans, with three past Major winners among them - Kvitova, Sharapova and Pennetta. Only Kvitova and Sharapova have tasted success at this prestigious event.
The tournament proper, which kicks off tomorrow, will be a battle of contrasts, pitting pedigree and experience against pluck and form; power and strength against elegance and speed.
In an event where every match has a heightened intensity, perhaps reigning US Open champion Pennetta summed up the battle ahead best.
She said: "These are the best players of the world. It doesn't matter who we're going to face - it's going to be tough anyway."
Come tomorrow, the players will shed their shimmering dresses and five-inch heels. The headbands will come back on and their weary bodies will be taped up again for battle.
But any fatigue will have to be cast aside - the race for the Billie Jean King trophy is on.