Pep Guardiola is weighing his depleted options on the right side of defence after admitting that both Bacary Sagna and Pablo Zabaleta are sidelined for Tuesday's tussle with Barcelona.

A natural option in that position is Pablo Maffeo, the ex-Espanyol youngster who made his second Manchester City appearance in the League Cup against Manchester United last Wednesday, but his lack of experience against such a potent strike force would pose a legitimate concern.

"We have to think we've not got right-backs," Guardiola told reporters. "We have one who recently played there and one who is 19.

"They have some important players out and we have to learn from the first game."

Fernando, the seldom-used defensive midfielder, has emerged as an option at right-back, but his deployment in an unfamiliar role would also prove a defensive risk. In addition, his limited mobility could be a hindrance to the fluid attacking play Guardiola implements.

Another alternative would be a strict back three, with a winger dropping slightly deeper in the system as a wing-back.

City isn't alone with its selection headache, however, with opposing boss Luis Enrique trying to devise ways to overcome the injury losses of Gerard Pique, Jordi Alba, Andres Iniesta, and Jeremy Mathieu, though Mathieu would have been suspended for the match after being sent off in their last meeting.

The two teams' last group-stage meeting came two weeks ago, when City ran close to Barcelona until goalkeeper Claudio Bravo's dismissal sparked a collapse from the Premier League leader. City succumbed to a 4-0 defeat at the Camp Nou, with Lionel Messi bagging a hat trick.

"I have never thought that we can't win a football match and I never will. Even when we lost 4-0," Guardiola continued. "It's difficult and we know we need to play almost perfectly to win - and if not, we will congratulate them and move on.

"Maybe we are going to change the way we press, our build up, control. I would like to play in good level for 90 minutes."

City has four points after three matches in the Champions League's Group C, one point ahead of Borussia Monchengladbach and two above Celtic. Barca, meanwhile, has a perfect record and whopping +12 goal difference so far.