16:00 BST, Sunday 24th June, Central Stadium (Yekaterinburg, Russia), BBC
Both of these teams were somewhat surprise winners in their opening game, with Colombia and Poland the teams largely tipped to progress from this open group.
Japan pulled off an impressive 2-1 victory over a much-fancied Colombia side. Playing a majority of the game against ten men after Carlos Sanchez was sent off, the Blue Samurai made their numerical advantage count despite facing a determined Colombia team.
Senegal, similarly, ran out 2-1 winners over Poland. Aliou Cisse’s side started with the belief that they can win the game and, despite Poland rallying in the second half, saw the job through to the very end.
A win for either side in this game will all but ensure that they are through to the second round. Senegal will be keen to close business before they have to face a Colombia team with huge support in the final game, and the same goes for Japan.
Last Time Out
Poland 1-2 Senegal
Although Senegal ran out 2-1 winners, it was a tale of two halves.
In the first half, The Lions of Teranga played with great zest, dynamic going forward and were duly rewarded in the 38th minute when Idrissa Gueye’s shot deflected off Thiago Cionek and past Wojciech Szczesny in the Polish goal
Poland recovered in the second half, but were hit by a sucker punch just past the hour. Grzegorz Krychowiak’s back pass to Szczesny left him in a 50-50 for the ball with Mbaye Niang and the speedy Senegal attacker made it two, capitalising on the mistake.
Krychowiak made amends on the 84th minute when his looping header beat Khadim N'Diaye, to set up a grandstand finish. Senegal saw the game out to claim a vital three points and the first win by an African side at this World Cup.
Colombia 1-2 Japan
An early red card after a handball by Carlos Sanchez saw this game blown wide open in just the third minute. That handball prevented an attempt at goal by Shinji Kagawa and the attacking midfielder converted the spot-kick to make it 1-0.
Colombia were undeterred by the numerical disadvantage and played their usual creative game. Their reward came in the 40th minute when Juan Carlos Quintero fired in a low free-kick under Japan’s wall, which squeezed in past a scrambling Kawashima.
That equaliser gave Colombia the momentum going into half-time, but it was Japan that came out in the second half rejuvenated. In the 71st minute, their man advtnage finally told as Osaka rose highest to head home from a corner.
Japan are not expected to make any changes after their impressive 2-1 win over Colombia.
Akira Nishino was satisfied with the performance, with Osaka justifying his selection over Shinzi Okazaki, so he's unlikely to change a winning formula.
Captain Cheikhou Kouyate was a surprise omission from the starting XI in the World Cup opener, but he is expected to start on the bench once again.
Diafra Sakho could replace Mame Biram Diouf up front as the Stoke striker didn’t have much to offer against Poland.
These, however, are minor selection issues Aliou Cisse will ponder. The likelihood is he will start with the same team as last time out.
Key Battle: Sadio Mane (Senegal) vs Shinji Kagawa (Japan)
This game will see two of the finest attacking midfielders to come out of Africa and Asia in recent years.
For true greatness it is these kinds of games at the World Cup where they are expected to make the difference and shine for their nations.
For Japan, Shinji Kagawa represents a breed of midfielder that Japan did not regularly produce until recent years. Able to make timely runs into the box, he is the most high profile, most refined of them all, and a good performance and a win here would staple his status.
Senegal simply don't produce footballers like Sadio Mane frequently and he shows that even in a physical team like Senegal there can be some elfin flair.
He is now a widely revered player, as he showed in the Champions League final, and dragging his team to the second round would see him give Mo Salah a good run for his money in the African Footballer of the Year stakes.
Can Japan handle Senegal’s physicality?
Four years ago Japan lost 2-1 to Ivory Coast despite outplaying them. They went into half time winning 1-0 having out-passed them and beaten them in the key duels, with the Ivorians struggling to cope with their movement.
However, Didier Drogba changed the game. He didn't get on the scoresheet, but his physicality caused the Japanese problems in the box, epitomised by the fact that both goals came from headers.
Senegal are arguably the most physically impressive side in Africa with most of the squad registering at six feet or over, and they would be wise to copy Ivory Coast’s approach from that match in 2014.
This will have an advantage at set pieces in particular, with the likes of Kalidou Koulibaly thriving in such situations.
Can a Senegalese striker make the position his own?
While Japan striker Yuya Osako justified Akira Nishino's selection versus Colombia with a goal and an all-action performance, making runs and tracking back to make a crucial block, Mame Biram Diouf did the opposite.
For a long time the Senegal lone striker role has been up for grabs but Diouf, Moussa Sow, Diafra Sakho and Moussa Konate have yet to make their position their own.
After his ineffective performance against Poland, it would not be a surprise to see Diouf make way for Sakho.
Whatever Cisse opts for, the question remains: can the striker justify his selection at least for the remainder of this tournament? Diouf has always been the surest bet, but lately he has been playing himself out of the team.
Prediction: Japan 1-2 Senegal
Senegal are flowing with confidence right now, with only one loss in their last 11 games, and Cisse will ensure his side see the job through. Their physicality and the aerial threat they will provide at set pieces should be enough to see them edge this.
Listen to the RealSport football writers discuss all the action from Day 8 of the World Cup in Kremlins in the Basement: RealSport’s daily World Cup podcast.