Two weeks ago Lancaster stated it would be a “big step” to include Dewsbury-born Burgess and Slade alongside Brad Barritt and Jonathan Joseph in the final 31-man squad due to their lack of Test experience.
Days later they made strong debuts in the 19-14 victory over France at Twickenham and after impressing throughout the summer-long training camp, head coach Lancaster took the bold step yesterday of naming both in his World Cup squad.
It means England’s four centres have only 36 caps – 22 of them supplied by Barritt – but Lancaster is satisfied he settled upon the right blend of centres.
“I wouldn’t say it’s a risk, it’s exciting,” said Lancaster.
“The France game at Twickenham was a key moment for Henry and Sam and was a reflection of what we had seen in training over the last eight weeks. They both delivered.
“The impact both have made in training is huge. On Wednesday it was the same. There never is one moment in selection. It is a picture you build up over time. They have both been excellent and deserve their chance.”
Former Bradford Bulls star Burgess won the battle of the gainline bruisers after fellow Yorkshireman Luther Burrell was told by Lancaster that he had lost out to the player who switched codes from rugby league 10 months ago.
It was a tight call that had clearly taken an emotional toll on Lancaster, but the head coach was ultimately swayed by the presence of Burgess in attack and defence.
“Sam certainly brings physicality at 116kgs and is as quick as any of our centres, except for Joseph, and certainly as quick as Luther,” said Lancaster.
“He is powerful and understands and reads defences very well. He is a very aggressive tackler, but one of his main attributes that goes unnoticed more than anything else is that he runs effective lines, even when he doesn’t get the ball.”
Ben Morgan, who made his comeback from the broken leg suffered in January to face France on August 15, edged Nick Easter at No 8 when he confirmed his fitness on Wednesday afternoon.
“At the end when we are doing fitness, we have all the back rows in a line sprinting up and down the pitch. Ben is definitely up to that speed,” said Lancaster.