I'm always keen on cards whenever there's an Argentina v Brazil clash in the South American continental competitions and this game certainly has all the ingredients for them.
For a start, it's 0-0 after last week's first leg so there's very much still everything to play for.
That contest saw six cards, three for each team, continuing both teams' good record for collecting cards in this tournament.
Each side has now received 21 cards in seven matches in this season's Copa Libertadores which even by South American standards is pretty good going - we're down to the last 16 now and of those left, these two sit third and sixth respectively in the cards rankings.
Crucially, we've also got a referee with a great track record for cards.
Uruguayan Andres Matonte has this season shown 91 yellows and 12 reds in his 17 matches in all competitions, averaging almost bang on six per game.
In the Libertadores, he's produced 38 yellows and three reds in seven games, keeping him level with his efforts in 2021 (31 cautions & 2 dismissals in 6 matches).
Over 6.5 cards looks to have every chance at 2.01/1 but for the big bucks it's to the 'player shown a card' market we turn.
This is often the best way of grabbing some value in such matches and two men - one from each team - stand out here.
Both play in midfield where the battle should be keenly fought given chances were at a premium in the first leg.
First up for the hosts, Guillermo 'Pol' Fernandez looks a big price at 3.7511/4.
He's been carded in eight of his 26 starts for Boca, a statistic which immediately makes the odds look big - and that's before taking into account everything I've written above.
For the visitors, Roni at 3.39/4 is the standout pick.
He's received a card in six of his 14 appearances this term, collecting three in his eight starts.
Clearly he's been on the bench a few times but he started last week's first leg, earning a yellow card in the opening 45 minutes, and the game prior to that.
The midfielder missed out at the weekend (due to suspension) but with Corinthians going down 4-0 to Fluminense, it's widely expected he'll return to the starting XI for this key game.
I really wouldn't be surprised to see the card count hit double figures here and if that happens there's a much better chance than 13.012/1 about these two being among those troubling the referee.
A two-legged Bet Builder is therefore the call.