Gareth Southgate says their training sessions have been rigorous. Photo: Toby Melville/Reuters

LONDON England's smooth progress towards a place in next summer's European Championship is a blessing and a curse, according to manager Gareth Southgate.

England crushed Bulgaria 4-0 at Wembley on Saturday with a hat-trick by Harry Kane and a goal for Raheem Sterling.

The win put England top of Group A with three wins out of three and they will expect to make it four when they host Kosovo in Southampton on Tuesday.

England are now unbeaten in their last 42 Euro qualifiers, a record dating back to 2009.

Southgate was pleased, especially, with the second-half display against Bulgaria but admitted the standard of opposition caused its own difficulties.

"We have not had the tight, tense matches that the Nations League provided as of yet," Southgate said.

"(Matches) that really we learnt so much more from. So therefore, we have got to do that in training and the challenge of training has got to be so high that we learn from those moments and we can see what the players are capable of."

Southgate led England to the semi-finals of the Nations Cup earlier this summer, having taken them to the same stage of the World Cup in 2018.

England have been able to give time to some younger players so far, with Jadon Sancho, Mason Mount, James Maddison and Trent Alexander-Arnold all on the bench against Bulgaria.

Despite the relative lack of test, Southgate said he feels his side have progressed since the World Cup, although losing to the Netherlands in the semis of the Nations League was a disappointment.

"Once you are in the semi-final, you want to go on and win the thing," he said. "But also (that came) with unique circumstances, in that seven players arrived 48 hours before the game."

Southgate said England are now right up there with some of the best teams in the world. "I think we are competitive with probably eight teams," he said.

"I think that, on our day, we can beat those teams, but equally the Dutch showed that they are capable of beating us on their day and I think it really is a tight grouping of probably eight teams."

Southgate is likely to give some of his youngsters a run-out against Kosovo at St Mary's Stadium on Tuesday, even if Kosovo sit second in the group.

Kane's second hat-trick of his England career took his tally to 25 in 40 appearances.

Southgate said Kane, who scored two of his goals from the penalty spot, set the perfect example both as captain and through his performances.

"I can only talk glowingly about that mentality to want to be a top player," he said. 

"Selfish isn't the right word because he's actually a very unselfish player. But, when he gets his moment, he has an outstanding mindset and, technically, he's a top finisher.

"But I go back to the fact that's hours and hours of practice and if you talk to some of the other forwards in the squad, they would talk to you about how big an impression that has had on them."