Pep Guardiola has confirmed that Josko Gvardiol is a doubt for Tuesday's Champions League quarter-final first-leg tie against Real Madrid at the Santiago Bernabeu.

The Croatian defender has become a first-team regular at left-back for the Citizens since joining the club from RB Leipzig last summer, starting 28 times across all competitions.

Gvardiol, who has also played at centre-back, was named in the starting lineup for City's 4-2 win at Crystal Palace in the Premier League last weekend.

However, the 22-year-old was taken off at half time, with Guardiola stating after the match that the defender "felt a niggle and we didn't want to risk any injuries."

Gvardiol was not spotted in an open training session on Monday afternoon, but he has been selected in Man City's 21-man travelling squad, unlike both Kyle Walker and Nathan Ake who have not made the trip to Spain.

Guardiola issues Gvardiol, Walker, Ake injury update

Ahead of Tuesday's Champions League showdown, Guardiola has confirmed that both Walker (hamstring) and Ake (unspecified) are still injured, while a late call will be made on Gvardiol's availability.

"[Gvardiol] travelled but he is a doubt," Guardiola said at a press conference on Monday evening.

"It is what it is. Also Madrid have [Thibaut] Courtois, [Eder] Militao and [David] Alaba, a long time they have been without players.

"It's true that the best player to control a player like Vinicius Junior is Kyle. He unfortunately, in a friendly game (on international duty with England), was injured. We would love to have him but what can I say?

"Injuries are part of a long season, but unfortunately in a decisive part of the season we have a number of injuries in the same area and we have to find a solution."

Who will play in defence for Man City against Real Madrid?

Guardiola has been boosted by the return of first-choice goalkeeper Ederson, who watched on as an unused substitute against Crystal Palace last weekend after missing the previous three games with a muscle injury.

However, Guardiola has admitted that he is yet to decide whether to recall the Brazilian or keep Stefan Ortega between the sticks against Los Blancos.

As for the back four, Ruben Dias and John Stones - the latter has only recently recovered from a groin injury - are the most likely candidates to start at centre-back.

Gvardiol will start at left-back if he is deemed 100% fit to begin the match, but his potential absence could see Manuel Akanji play on the left side of a back four, as he did for the second half against Palace.

Akanji is also an option to play at right-back and deal with the threat of Real Madrid's star winger Vinicius Junior, but if he is required to play on the left, then 19-year-old Rico Lewis is expected to get the nod at right-back.