Zinedine Zidane is back in charge at Real Madrid less than 10 months after stepping down as their boss.Real announced their reunion with the Frenchman on Monday as he replaced the sacked Santiago Solari.Zidane won three straight Champions League titles during his first spell in the Spanish capital, though it will require a monumental effort to achieve the same kind of dominance this time around.Madrid haven't ended a season without a single trophy in almost a decade, though it's clear they require a major overhaul.Here are the five key issues for Zidane to address on his return.

LIFTING AN UNMOTIVATED SQUAD

Real crashed out of the Champions League in the last 16 with a 4-1 loss to Ajax last week, their fourth straight home defeat.

It makes for some contrast to when Zidane departed in May, five days on from guiding them to European Cup glory for the 13th time in their history.

The time between his tenures, first with Julen Lopetegui and then Solari at the helm, has seen Real looking a shadow of their former selves and in considerable need of a lift.

Zidane, simply on the basis of the CV he has as a player and manager at the club, very much appears the man to provide that.

REPLACING CRISTIANO RONALDO

A major difference between the Real Zidane left and that which he is re-entering is Cristiano Ronaldo no longer being at the club.

Los Blancos’ all-time top-scorer moved to Juventus in July and their subsequent fortunes have only served to emphasise his absence.

It has been claimed by former Real president Ramon Calderon that Zidane had wanted Ronaldo retained and Gareth Bale sold – whether that is true or not, he must find a way to be successful without the Portuguese.

HANDLING GARETH BALE

It will certainly be interesting to see how things play out from here between Zidane and Bale – the most high-profile member of his attack now Ronaldo is gone.

The Welshman has spoken of the frustration he had felt at being left out of the starting line-up by Zidane for last season’s Champions League final win over Liverpool, in which he memorably came off the bench and scored a spectacular overhead kick.

After Bale, who has netted 13 times this term, was jeered by Real fans during the 1-0 loss to Barcelona on March 2, his agent Jonathan Barnett last week insisted the 29-year-old was “happy” and intended to stay beyond the summer.

He was not involved in Sunday’s win at Real Valladolid having ended the Ajax match with an ankle injury.

RESTORING UNITY

There have been various reports of disharmony in the Real Madrid camp, with club captain Sergio Ramos responding to questions about some of them via Twitter on Monday.

Whatever has been going on internally, Zidane will want to create as great a sense of unity as possible as he looks to revive the place.

NURTURING YOUNG STARS

Undoubtedly the summer promises to be fascinating in terms of players leaving Real and the club bringing signings in.

And while Zidane, who has been handed a contract to 2022, will surely want some new blood, something else to consider in his mission to drive Real forward is the exciting young talent already in the squad, such as teenagers Vinicius Junior and Brahim Diaz.

If nurtured well, they could have significant roles in his second spell in charge.