Pep Guardiola has claimed Manchester City could be “in trouble” following John Stones’ latest injury setback.

The treble winners are awaiting assessments of the England defender after he was forced off with a knock in Tuesday’s 3-0 Champions League stroll against Young Boys.

Stones only returned to action in October after a two-month lay-off with hamstring and hip problems.

Manager Guardiola said he feared the 29-year-old could be out “for a while” with the muscular problem and described the blow as “deep bad news”.

Stones has been revelatory for City playing in a hybrid defence-midfield role and Guardiola feels he complements central anchor Rodri perfectly.

Much was made of the fact Rodri was suspended when City lost three successive games earlier in the campaign, but Guardiola believes the absence of Stones was equally crucial.

He said: “The problem is we play John and Rodri at the same time – now we are in trouble, because we have to play a bit differently, like happened in Arsenal.

“We do not feel comfortable still, we are not prepared to change many variations.”

City hardly broke sweat as they brushed past the Swiss champions to secure their place in the last 16 for an 11th consecutive year.

The holders have won all four of their matches in Group G and are through with two matches to spare.

Erling Haaland made light of the ankle problem that curtailed him against Bournemouth last weekend to open the scoring with a penalty and added the third goal with a powerful long-range strike.

It was yet another dominant performance from the Norway striker, who has now scored 39 goals in 34 career Champions League appearances and 15 in all competitions this season.

Opposition captain Mohamed Ali Camara even asked to swap shirts with the 23-year-old at half-time, something which drew criticism in some quarters.

“I’m a little bit surprised about that right now,” admitted Young Boys coach Raphael Wicky, whose side failed to muster a single shot and had midfielder Sandro Lauper sent off in the second half. “I’ll probably have a word with him.”

None of this worried Guardiola, whose side looked comfortable with Phil Foden also on the scoresheet.

“It’s not normal, but I don’t know the reason why it happened,” he said. “It’s not a big subject for me right now.”

City’s remaining task in the group will be to secure top spot, and a theoretically favourable draw, in the first knockout round. They face second-placed RB Leipzig at home later this month before wrapping up the stage at Red Star Belgrade.

Midfielder Matheus Nunes said: “We cannot look at those two games as spare because we want to get through as first place, and that’s what we will try to do now.

“We will focus on Chelsea now, but when those games come we will be ready because we want to win both of them.”