In the match which will decide who finishes top in Group G, Southgate dismissed suggestions that there would be any circumstances in which England would not play to win despite opting to rest so many key figures.
Entering the game on identical points and goals records - after each opened with two successive wins -England had the edge on its fair play record at the top of Group G.
Whoever of England and Belgium tops the group will face the second-ranked team from Group H, with the victor of the latter group to play the runner-up.
Martinez has suggested he could make wholesale changes to his side but at the very least is expected to rest defender Jan Vertonghen, winger Thomas Meunier and midfielder Kevin De Bruyne, who have all picked up a yellow card.
"Maybe we can use them to our advantage, individually and as team, if that opportunity arises".
Southgate acknowledges there is a balance to be struck between keeping his side fresh and injury-free and maintaining the momentum they have gained, particularly from the 6-1 crushing of Panama. The Chelsea star is likely to come up against team-mate Gary Cahill in the England defence and will be relishing to add to the two goals he has already scored and secure some bragging rights over his Chelsea collogue.
In Group H, Japan, Senegal and Colombia can all still qualify for the next phase. The other side of the bracket, where Belgium is, features Mexico, Brazil, Argentina, France, Portugal and Uruguay.
Belgium beat England, 1-0, to win Group G and officially set the bracket for the knockout stage of the 2018 World Cup.
Japan coach Akira Nishino has warned his players against complacency when they meet the already eliminated Poles.
"That's normally one of the stories that's always written about every hotel we stay at, there's always something close-by to distract us", Southgate said.
Rashford and Januzaj are undeniably big talents, but they've both had their ups and downs.
"There was a lot of tension in the air today and, in that regard, I think my team did very well". That would mean we top the group and then we can move forward.
"But Belgium are miles better than the other teams we've played so perhaps it's been a bit of a wake-up call for the players". Tomorrow we want to perform well but the priority is not to win.
The evening would ultimately end in frustration for Gareth Southgate, who will feel justified in making eight changes to his starting lineup, as his side's 12-match unbeaten run came to an end in Kaliningrad. "I don't think that in the World Cup you can be successful by trying to hope to get an easy path". I understand why people question those decisions, but we have to prepare the team in the way we feel right.
If Ocasio-Cortez wins the general election in the heavily blue district, she would be the youngest woman ever elected to Congress. Ocasio-Cortez successfully cast him as a tool of elite interests who cashed in on his power.
Liam Fox warned that taking "no deal" off the table during Brussels negotiations would weaken the UK's bargaining position. The party said Liberal Democrats leader Vince Cable would tell Saturday's rally that "Brexit is not a done deal".
Theresa May wants to sign a free trade agreement and negotiate a customs arrangement to ensure as frictionless trade as possible. The ministry said additional laws "will deliver the more significant policy changes needed as a result of our exit".
The 76ers could be another contender for Leonard, though they have yet to make a formal offer, according to Sports Illustrated . The two sides are said to believe a deal for Leonard would likely convince LeBron James to join the Purple and Gold.
An appeals court in Sudan has overturned the death sentence of a teenage-girl who killed her husband after he raped her. The court ordered her family to pay 337,000 Sudanese pounds ($18,700) in "blood money" to the man's family.
The Germany keeper bobbled the ball and needed to swipe the rebound away from the attackers after a spectacular dive. Germany made a nervous start, playing slower than it usually does to avoid being vulnerable on the break.
Beijing claims almost the entire South China sea and is fighting counter claims by many of its maritime neighbours. North Korea has long regarded the American troop presence in South Korea as a threat.
Mr Trump said Wednesday that "getting along with Russian Federation and with China and with everybody is a very good thing ". A statement from the White House said the men would also broach "a range of national security issues".