Competition: Gallagher Premiership
Venue: Twickenham Stadium, London
Date and kick-off time: Monday, December 27, 2021, 5pm
Weather forecast: 10c, light rain
Live television coverage: BT Sport 1
Referee: Wayne Barnes
Harlequins: Green; Lynagh, Marchant, Esterhuizen, Murley; Edwards, Care; Marler, Walker, Collier; Symons, Lewies (c); Lawday, Kenningham, Dombrandt.
Replacements: Musk, Garcia Botta, Kerrod, Tizard, Lamb, Gjaltema, Northmore, Jones.
Saints: Furbank; Sleightholme, Proctor, Dingwall, Skosan; Biggar, Mitchell; Waller, Matavesi, Painter; Ribbans, Ratuniyarawa; Lawes, Ludlam (c), Augustus.
Replacements: Haywood, Auterac, Hill, Coles, Wood, James, Hutchinson, Tuala.
Not considered for Saints selection: Callum Burns, Tommy Freeman, Teimana Harrison, Oisín Heffernan, Dani Long-Martinez, Alex Moon, Taqele Naiyaravoro, Kayde Sylvester.
Most recent meeting: Friday, November 19, 2021: Harlequins 26 Saints 25 (Premiership Rugby Cup pool stages)
Tom's preview: When Saints step out at Twickenham Stadium on Monday evening, they will do so on the seventh anniversary of a victory in the same fixture.
Back on December 27, 2014, Jim Mallinder's men marched to English rugby HQ and once again stamped their authority on a key Premiership clash.
Back then, Saints were the reigning champions, and they were able to finish off the best year in the club's history with an entertaining 30-25 win that put them top of the table.
Samu Manoa, George North and Kahn Fotuali'i - what a top trio, by the way - scored the tries and Stephen Myler did the business with the boot as Saints put Harlequins to the sword.
They would go on to end the campaign top of the Premiership tree for the first time in the club's history before losing to Saracens in the play-off semi-final.
And we all know how the seasons after that went.
Now though, Saints go back to Twickenham sitting pretty in the Premiership once more.
And what a win would do not only for their standing but their self-belief.
Having lost back-to-back matches in the Champions Cup, Chris Boyd's side could really do with a shot in the arm.
And if they they could see off a Harlequins side who look hungry for more glory this time round, it would be a real statement success.
It wouldn't quite lift them to the heights of 2014, but it would set them up very nicely for 2022.
They have the players available to get the job done, and they have been handed a sizeable boost with the news that they won't have to handle Harlequins magician Marcus Smith.
But the proof will be in the pudding on Monday evening as to whether they can deal with Smith's talented team-mates.
Quins have made a habit of winning big games in 2021 - and they will fancy themselves to prevail in Big Game 13.
But Saints have to take a leaf out of the book of that team that went before, in 2014.
That team feared no one, nowhere.
No matter the occasion, they could deliver, whether it be with overwhelming power or incredible precision.
That is the level this Saints team needs to get to not only in the final fixture of this year, but in the many ahead in the 12 months that follow.
Tom's prediction: Saints have most of their key men available for this huge match-up and they could really do with a win to cement their spot in the top four going into 2022. I fancy them to show up and deliver here. Harlequins 23 Saints 28.