Lionel Messi's final appearance at the World Cup could happen on Wednesday, should he and his Argentina team-mates slip up against Poland.
Argentina realistically need to win to secure their place in the last 16, a draw could also be enough for La Albiceleste, but they would then be relying on goal difference and the outcome of Saudi Arabia's clash with Mexico.
Two more World Cup groups conclude on Wednesday, with seven teams scrapping for three last 16 places, although defending champions France are already safely through in Group D.
Lionel Messi has scored in both of Argentina's games in Qatar, but the opening game loss against Saudi Arabia means that he and his La Albiceleste companions have their backs to the wall.
Lionel Scaloni's side are 1/5 to reach the last 16, but only a victory over Poland will guarantee their passage. This is widely expected to be Messi's final World Cup and - from here on - the pressure is ratcheted up.
Robert Lewandowksi scored his first World Cup goal against Saudi Arabia, and Poland's talisman is 10/3 to get what could be a crucial goal against the South American giants.
Mexico know they simply must win their final game against Saudi Arabia to have any chance of progress to the Round of 16 - something they've managed in their last five World Cups.
They have not had the best tournament so far, drawing 0-0 with Poland before losing 2-0 to Argentina, but they have the attacking players in their armoury to find a way past Saudi Arabia.
The Saudis, meanwhile, faltered against Poland - missing a penalty - after their heroic win against Argentina. They know a win here puts them into the knockout stages.
Many well-placed pundits had Denmark down as dark horses coming into the World Cup but the reality is last summer's Euro 2020 semi-finalists will be going home if they don't beat Australia.
Denmark toiled in their opener with Tunisia, looking toothless up front, before putting in an improved showing in Saturday's 2-1 loss to France.
Playmaker Christian Eriksen has yet to catch fire, but he is the man the Danes will rely on to unpick the Aussie lock. Graham Arnold's side are 16/5 to collect the point that will most likely take them through unless France lose to Tunisia.
Didier Deschamps' side are through with a game to spare and, given the injury woes that have beset Les Bleus before and during this tournament, he'll likely give some of his key men a rest against Tunisia.
Even allowing for that, the French should be too strong for Jalel Kadri's side. It would be a herculean effort if they get the three points they need to have a chance of progressing - and they are 20/1 to make the knockouts as they'll rely on things going their way in the other game, even if they do beat the world champions.
His Class of '92 compatriot Ronnie O'Sullivan blitzed his way to a century break in a little over three minutes and 30 seconds on Monday, but things have been a tad less sparkling for John Higgins this season.
The Scot has struggled to find the sort of form he showed last term, and will be hoping for a good run on home soil this week at the Scottish Open. Higgins is 2/5 for his tricky clash with Cao Yupeng (2/1) on Wednesday afternoon in Edinburgh.