This season's strictest Premier League referee takes charge of this game and, accordingly, a cards-based Bet Builder looks worth chancing.
Kevin Friend is averaging over six cards per game thus far and has shown at least two to each team in each of his five matches.
Admittedly West Ham have the best discipline in the top flight which helps explain why you can get close to 2/1 about it occurring again here.
But one of Friend's five games was when the Hammers headed to Leeds, while West Ham's dip in form - it's now just one win in seven matches in all competitions - means there's a real need to scrap for points in this contest. David Moyes' men only picked up one card at Tottenham in midweek but they adopted a very physical approach and we can expect something similar on Boxing Day.
Only Watford have committed more fouls per game than Southampton, who picked up three cards from Friend when they travelled to Chelsea in the EFL Cup.
Their battling qualities will also be required here given they've picked up just three points from the last 18 available to slip within six points of the drop zone.
Over 1.5 cards for each team certainly makes appeal at 2.8415/8 and is worth considering on its own.
However, for those seeking a bigger price, adding Mohammed Salisu to be among those booked for Saints takes the price to 8.27/1.
The left-sided centre-back has often looked shaky this season and it's no surprise to see he's had to take matters into his own hands on occasion.
It's now six cards in his last 12 league starts for the Ghanaian, who seems likely to be tested here.
Michail Antonio is not a certain starter following his bout of COVID-19 but potential replacement Andriy Yarmolenko can be a tricky customer, while Jarrod Bowen and Vladimir Coufal down his side of the pitch are both enjoying good seasons and should add plenty of threat for the hosts if, as expected, they make David Moyes' XI.
Of the league's centre-backs, only Wolves' Max Kilman and Leeds' Liam Cooper have made more tackles than Salisu so there's clear potential for him to be heading into Mr Friend's notebook.
Expected goals: Tom Victor's look at the Boxing Day games