John Stones to miss derby, Erling Haaland to battle old foe Lisandro Martinez

Pep Guardiola has praised his medical staff for keeping Erling Haaland fit and firing.

Haaland has made a stunning start since joining Manchester City in the summer, scoring 14 goals in 10 appearances in all competitions.

Despite boasting a prolific record throughout his young career, the 22-year-old has also had a number of niggling injury problems.

Yet with Haaland having so far started every game for City, Guardiola is hopeful they are now a thing of the past.

The City boss said: "Everyone is important but I've always said to the club that the most important department in the backroom staff is the physios. They take care of the legs.

"Erling struggled a lot in Dortmund last season with injuries and arrived here with little problems after a small surgery in the summer.

"He started to work here with (physiotherapist) Mario (Pafundi) and the other guys and thanks to them – and of course his work ethic – he can play regularly now. Last season it was not possible.

"When the players can play most of the time it’s thanks to the physios."

Pafundi even travelled with Haaland to work with the player and Norway during the recent international break.

Guardiola said: "It’s not weird. At events like World Cups and European Championships, many physios go with the players, and Mario is an exceptional physio."

Haaland faces his next big test as champions City host arch-rivals Manchester United at the Etihad Stadium on Sunday.

His battle with Lisandro Martinez, United’s impressive new centre-back, could be intriguing.

At 6ft 4in, Haaland has a clear height advantage over the 5ft 9in Argentinian, but Guardiola insists that does not necessarily offer an indicator of how the battle will be won.

Guardiola said: "Erling is taller, that is for sure, but