Lampard, who has been forced to turn to youth this season owing to the club’s transfer ban, named the youngest side in the club’s Premier League history, with an average age of 24 years and 158 days.

He handed a first start to 21-year-old Fikayo Tomori and brought on 18-year-old midfielder Billy Gilmour for his first appearance.

But for all their youthful energy, their soft underbelly was exposed, though Lampard says the two are not related.

“I don’t put that together and I couldn’t care less that we had the youngest team in (Chelsea’s) Premier League history,” he said.

“It was a real plus last week. The fact that it is young today, I don’t think it relates at all.

“The lack of concentration caused mistakes for the goals, but you defend as a team as much as attack.

“We concede because we switch off in a game we should be comfortably seeing out at 2-0 up. That’s not disrespecting to Sheffield United, 2-0 is not the end of the story.

“I was clear with the players at half-time that it could 3-0 and be nice or a potential 2-2 on our hands so the disappointing fact is the first goal because that allowed it. We can only look at ourselves as a group.”

Lampard defended his decision to bring on Gilmour for his first senior appearance when the game was in the balance.

“It wasn’t bold. (Mateo) Kovacic was on his haunches, obviously tired and Billy Gilmour is a midfield player I have got on the bench,” he said.

“Other people can make what they want of that, but I wasn’t trying to be clever, I was trying to see the game out.

“I have got faith in Billy I think he is going to have a big future, but we have any injury in midfield, with N’Golo (Kante) who is a good player. But we have a ban, the squad is what the squad is.”

The average age of the squad would not have been an issue and Chelsea seen the game out which they should have done from a 2-0 half-time advantage.

Abraham scored his second successive brace after capitalising on errors from Dean Henderson for his first goal and John Egan and Jack O’Connell for his second.

It took his tally to four for the season and perhaps put question marks over Gareth Southgate’s decision not to include him in his England squad for next week’s Euro 2020 qualifiers.

But Robinson’s first goal for the Blades 48 seconds after the restart gave Chris Wilder’s men the impetus and Zouma’s own goal, when he turned in Robinson’s inviting cross, earned a deserved point.

Wilder said: “We had to play well here, we can’t give ourselves a mountain to climb, which we obviously did.

“To come roaring back as we did in the second half hopefully gives us an enormous amount of confidence and self-belief going forward.

“I don’t want us to stand off teams, we obviously understand the teams we are up against and the journey we have been on.

“Three years ago we were bottom of League One and now we are going toe-to-toe in the Premier League. It’s not a cup tie, we are here on merit.

“From a biased point of view, I believe we deserved something from our second-half performance.”