Why Manchester City manager Pep Guardiola will not be in the Sheffield United dugout on Sunday

It is less than three weeks since Lillo's return to the club was announced after the departure of Enzo Maresca to manage Leicester City, but he did have an earlier two-year spell at Eastlands, and has an extensive CV as a head coach.

Guardiola is not expected to return from Spain, where he is convalescing, until after September's international break. It means he is also expected to miss the September 2 home game against Fulham.

His club revealed the 52-year-old "has been suffering with severe back pain for some time lately, and flew out to Barcelona for emergency surgery performed by Dr Mireia Illueca.

"The surgery was a success, and Pep will now recover and rehabilitate in Barcelona.

"In his absence, assistant manager Juanma Lillo will oversee coaching of the first team on the training field and will assume duties on the touchline until Pep’s return,' City added.

"He is expected to return after the forthcoming international break."

Lillo first joined City in 2020 as Mikel Arteta's replacement but left to manage Qatar Stars League side Al Sadd in 2022.

The 57-year-old has also managed Amaroz, Tolosa, Mirandes, Cultural Leonesa, Salamanca, Oviedo, Tenerife, Zaragoza, Ciudad Murcia, Terrassa, Real Sociedad, Almeria, Millonarios, Atletico Nacional, Vissel Kobe, Qingdao Huanghai and Dorados Sinaloa, where his players included veteran midfielder Guardiola.

Fellow Spaniard Carlos Vicens will assist Lillo.

The Covid-19 pandemic has taught managers to be more effective at managing remotely, with Paul Heckingbottom missing a game at Derby County in 2021-22 after contracting the virus.

Then-Rotherham United manager Paul Warne even gave team talks when isolating at home.