Erling Haaland was withdrawn at half-time in Manchester City's Champions League draw with Borussia Dortmund due to a fever and a knock to the foot.

City were held to a 0-0 draw at Signal Iduna Park on Tuesday, with Haaland taken off at the break after an uncharacteristically quiet first half.

Pep Guardiola confirmed after the match that the Norway striker – and Joao Cancelo, who was also brought off at half-time – had been struggling before the game with a minor illness.

Haaland also received a blow to the foot, though Guardiola did not suggest his condition was of major concern, with the striker appearing jovial as he greeted his former Dortmund team-mates on the pitch at full-time.

"Erling didn't feel good, he had a little fever before the game, Joao as well," Guardiola told BT Sport.

"[Haaland] had a knock in the feet. That's why we changed it, and in that period we struggled a lot."

The draw was enough for City to secure their progress as Group G winners, with Dortmund also confirming qualification for the last 16.

However, City should have left with all three points.

Riyad Mahrez won a second-half penalty following a clumsy Emre Can foul but his resulting spot-kick was saved by Gregor Kobel.

That was the 25th occasion of City failing to convert a penalty since Guardiola took over in 2016 (out of a possible 80), more than any other Premier League side over the same period.

"Of course it's a problem. Since I'm here it's 24 or 25 penalties [missed], most of them in the Champions League," Guardiola said.

"It's too much. I always admire the courage, the responsibility [to take a penalty], but of course we miss a lot and it's a problem.

"We have to improve otherwise these little details, these margins in this competition, it's the difference [between success and failure]."

It was also Mahrez's third penalty failure in his past four attempts, though Guardiola is not going to stop him taking future spot-kicks.

"I admire the courage. Riyad, with the last penalties scored a lot last season in important moments, so in that situation I admire the courage," he added.

"If he feels [able] next time he has a penalty, he's going to take it. But of course we have to improve."