World Cup 2018: Was the loss to Belgium a reality check for England?

England suffered their first World Cup defeat as they were beaten by Belgium to finish second in Group G.

Manager Gareth Southgate must now prepare to face Colombia in the last 16 in Moscow on Tuesday after both he and Belgium counterpart Roberto Martinez fielded teams that were unrecognisable from their strongest line-ups.

As England move into the World Cup knockout stage, what are the lessons of their setback in Kaliningrad?

• Colombia game is England's biggest knockout tie for a decade, says Southgate

• Colombia fret on Rodriguez fitness before England last-16 tie

• Player Rater: England v Belgium

Reality check or phoney war?

For all Southgate's insistence that victory was all in this final group game, a starting line-up containing eight changes from the win against Panama was hugely informative.

And his refusal to send on captain Harry Kane even as England struggled for an equaliser proved his sights were fixed on the knockout stages.

It led to an unreal atmosphere and a game that sometimes resembled a battle no-one wanted to win, summed by the sound of Belgium supporters cheering yellow cards, knowing their inferior disciplinary record could see them fail to win the group and plot a potentially easier route around Russia.

England's defeat sends them to Moscow to face Colombia - so was this the first reality check for Southgate and his players at a World Cup that has gone so smoothly or simply a glancing blow delivered in a phoney war?

In reality, the answer can only be given after Tuesday's last-16 game when Southgate's England are restored to full force.

If England win in Moscow, it will be a case of no harm done and they can march on to a winnable World Cup quarter-final against either Sweden or Switzerland. If they lose then this game will be viewed as the night when vital momentum was lost.

Southgate gambled here. The outcome of this throw of the dice will be known on Tuesday.

Momentum is a crucial commodity in tournament football and England sacrificed some here, although that must be qualified by that much-changed starting line-up.

It was obvious Belgium's reserves of strength are vastly superior to England's - Martinez's dirt-trackers, to use a rugby phrase, are fitter for purpose than Southgate's.

Belgium have the resources to better overcome the absence of the likes of Romelu Lukaku, Kevin de Bruyne, Eden Hazard, Dries Mertens, Toby Alderweireld and Jan Vertonghen.

Southgate simply does not have that power at his disposal. This was confirmation that Kane is indispensable.

Did England's undercard stake their claim?

Tottenham's Eric Dier - a pedestrian display in midfield against Belgium

Southgate's selection gave some of England's under-utilised squad the opportunity to make him sit up and take notice for the knockout stages.

Very few took their chance - although two certainly sent a message to their manager.

Liverpool's 19-year-old Trent Alexander-Arnold proved his big-match temperament as a right wing-back, although it was a mistake to entrust him with so many set-pieces, where his delivery was poor.

And while Tottenham's Danny Rose was caught for Adnan Januzaj's winner, he did enough in defence and attack to emerge as a real threat to Ashley Young as England's left wing-back.

Former England defender Martin Keown told BBC Sport: "I'd have him in the team because of the balance he has. You can see he has got himself together and he played very well. I would keep him in the side - that would be tough on Ashley Young but you need that left-footed player in the team."

The downside came in the poor display from Eric Dier, whose pedestrian effort cemented Jordan Henderson's place as midfield anchorman while Phil Jones did nothing to suggest he would be a significant figure again.

Jamie Vardy and Marcus Rashford were energetic but lacked punch. Kane, Jesse Lingard and Raheem Sterling must provide the attacking thrust against Colombia.

Ruben Loftus-Cheek also had a quiet night, so Southgate will be even keener to bring Dele Alli back into the fold as he continues to try to overcome the thigh injury he suffered against Tunisia.

If Southgate learned lessons from this, it is that he got his original World Cup selection pretty much spot on. The bulk will be back against Colombia.

• World Cup Daily podcast: Is football still coming home?

Lucky break or high-risk strategy?

There is a doubt over the fitness of one of Colombia's key players, James Rodriguez

England now know what awaits them. They face the dangerous Colombia and will meet the winner of Sweden against Switzerland in the last eight if they come through.

Colombia have grown into this World Cup and cannot be taken lightly. Any underestimation will be heavily punished.

England, however, will gain advantages from finishing second in Group G.

Southgate's side will avoid a potential meeting with Brazil in the last eight. This has to be regarded as a plus.

They will get an extra day to prepare because, if they had won the group, they would have gone to Rostov to face Japan on Monday.

England's travelling will also be easier and they will undoubtedly benefit from a better climate in Moscow, where it is expected to be around the low 20s.

Southgate and his backroom team will have noted reports from the furnace of Rostov, where temperatures have gone into the 40s. Moscow will be much more to England's liking.

This was a surreal occasion with two shadow squads. England and Southgate will discover on Tuesday whether their clearly conscious decision not to go all out for victory will be the right one.

• Easier half of the draw?

England would face Sweden or Switzerland in the quarter-finals if they beat Colombia