The Spaniard was appointed into the Bramall Lane hotseat following the surprise sacking of Chris Wilder after the Blades’ play-off final defeat, but his stint could not have begun any worse.

Scott Twine’s double and goals from Ross McCrorie and Anis Mehmeti ensured Gerhard Struber’s first game in charge of the Robins was a much more enjoyable affair.

Tyrese Campbell had levelled for the Blades but this performance will raise big questions about their promotion credentials this term as they were booed off by their unforgiving fans.

“It was absolutely not the start I wanted,” Selles said.

“We were to open in transition and they took great chances, so disappointed on that. I think we can, we should and we must do better.

“We were way too open, we were not structured enough.

“It was a disappointing day. The fans came here to see a performance and see a team chase a win and we end up in a bad day with a bad result.

“I am not going to tell anyone what to say, I think losing 4-1 you can understand it.

“I’m the first one to take responsibility for that. I think there is a second point about doing it together. And then there’s a third point about, how do we show that character straight from now, straight from the next 24 hours, when you need to feel that pain, but you need to be sure that you are ready to go again.”

Bristol City boss Struber enjoyed a much more enjoyable first game in charge of his new club.

The Austrian, who managed Barnsley between 2019 and 2020, took over following Liam Manning’s move to Norwich and will have liked what he saw.

However, he is not getting carried away after being asked whether promotion was an ambition.

“It was a really good performance for my boys today. We expected a good performance but the result of this level against the opponent on this level, it’s a small surprise,” he said.

“But this shows we are in the right way. A win like this at this level gives everyone good self-confidence.”

“I’m not thinking about promotion, thinking about promotion would not help me.

“We should focus completely on ourselves. We have to do so many things on a top way that we should think so much more in the here and now and not what is going on at the end of the season.

“We have 45 games left, it is very important to be focused and close. We want to grow our standard but we are not the team to speak about promotion.”