The Pies will be looking to stay inside the top four, the Blues smell blood, while an emerging Saint gets to prove himself.
Here's What To Watch For in Round 19.
Collingwood to drop out of the top four
Without being too hyperbolic, Collingwood's season hinges on the result of their clash against Richmond on Friday night.
It seems absolutely crazy to think the Pies could fall to as low as seventh with just one more loss, but that's the stark reality for Nathan Buckley and his troops ahead of Round 19.
Since their seven game winning streak which ended in Round 10, the Pies have gone 3-4 and look a completely different side to the one many of us had just about locked in for another Grand Final berth. They are struggling to defend, struggling to move the ball and now struggling to score.
On Friday night they face the red-hot Tigers at the Melbourne Cricket Ground and it's a game which almost certainly will determine whether or not they are going to be a threat in September.
After this week, Collingwood's remaining four games are against Gold Coast (MCG), Melbourne (MCG), Adelaide (Adelaide Oval) and Essendon (MCG), so it's far from a guarantee they will finish with a flurry.
A loss to Richmond would be catastrophic and you would almost have to put a line through them as it's highly unlikely they would produce a Western Bulldogs-like 2016 finals run, particularly given that they are spluttering at the wrong time.
Having said this, the last time we doubted Collingwood's flag credentials they came out and stunned West Coast at Optus Stadium. Could they possibly do it again?
The Blues to get the upper hand in the Adelaide pick swap
Even a few weeks ago, uttering the words "break even" in relation to Carlton and Adelaide's historic live pick swap would have been met with raised eyebrows.
For those who might have forgotten the details, during last year's national draft, the Blues shipped their 2019 first-round pick to Adelaide for pick 19 (Liam Stocker) and their first-round pick.
As it stands, the Blues are sending pick 3 in exchange for Stocker (already on their list) and pick 11, but the Blues are in good form, and the Crows... well, not so much. So is it beyond the realms that 16th placed Carlton can knock off the 8th placed Crows at the MCG on Saturday afternoon and swing the proverbial needle their way?
In short, no. Carlton are playing an attractive and attacking brand of football not seen since the Brett Ratten days, while the Crows have been made to look old and slow in recent weeks. Adelaide's record at the MCG doesn't make for good reading either; they played there twice last year for two big losses - by 47 points to the Tigers and 56 points to the Hawks. They're yet to play at the home of footy this season.
Adelaide can also expect a hostile crowd at the 'G, and not only because this is Carlton's 'Grand Final'. The Blues are smashing membership and crowd records despite their dour season, and last week posted their highest ever attendance against the Suns. The MCC is predicting a crowd of more than 46,000 on Saturday - which would be Carlton's largest ever home-and-away home crowd against the Crows.
Should the Blues win on Saturday and other results fall the way of the favourites, Carlton moves level with Sydney on 24 points -- and within striking distance of 15th spot on the ladder -- while the Crows open the door for a number of other teams to enquire about the final spot in the eight.
It's fair to say there hasn't been this much intrigue surrounding a Round 19 match involving Carlton for some time, so tune in on Saturday for the Liam Stocker Cup.
Is there now a 'Big 3' ruck echelon?
Rowan Marshall's rise has been meteoric this year and he's rapidly making ground on the league's 'Big 2' rucks, Brodie Grundy and Max Gawn.
The St Kilda big man was overlooked for selection in the opening round of the season but has since stated his case to be the AFL's most improved player in 2019: Marshall is ranked eighth in total hitouts this year and is averaging 17 disposals, four marks and an impressive five clearances and four tackles a game.
And he has taken his game to new heights in the past four weeks, becoming the league's No. 1 score assist player as well as being top of the tree in Champion Data's Player Ratings points.
After years of Grundy and Gawn being head and shoulders above their peers, Marshall is quickly making his case to join them as a 'Big 3' and his efforts against Gawn will go a long way to deciding the St Kilda vs. Melbourne clash at Marvel Stadium on Saturday night.
He will have to be at his best to help St Kilda win the midfield battle, with the Demons rediscovering one of their 'one woods' from last year in recent weeks: scoring from stoppages. In that stat, the Dees have become the No. 1 team in the league in the past month after ranking last from rounds 1 to 14, with Gawn's improving form a key part of that.
Can Marshall continue his rise or will Gawn prove there's still a bit of a gap between the 'Big 2' and the rest?