Luis Suarez will be up against his former club when Atletico Madrid play Barcelona at Camp Nou on Sunday. (AFP)
Both clubs have endured the kind of turbulence this season that neither have faced for more than a decade but each of them head to Camp Nou with fresh hope and a sense of optimism that a corner is being turned.
Sunday will mark exactly two months since Xavi Hernandez was appointed Barcelona coach, with the team lying ninth in La Liga, five points adrift of the top four.
The trajectory since has not always been upward, with failure to qualify for the Champions League knock-out stages preceding defeat by Athletic Bilbao in the last 16 of the Copa del Rey.
Under Xavi, Barca have lost at home to Real Betis and drawn away at Osasuna, Sevilla and Granada. Even in their last game against Alaves, which brought a 1-0 win, the lack of punch and creativity was arguably as clear as it ever was under Ronald Koeman.
But there is evidence now of a system and a plan, even if these players are not always capable of executing it.
Results have improved – Barca have lost only once in the league in Xavi's 10 games.
And youngsters have taken another step forward, with Nico Gonzalez, Gavi and Ronald Araujo forming the beginnings of a spine around which this team might be able to build.
Most importantly, Barca have closed the gap, with just a point now separating them from Atletico Madrid in fourth, meaning a win this weekend would lift them into the Champions League qualification spots for the first time since September.
For all the excitement about Xavi coming home and a new generation coming through, Barcelona cannot afford to wait.
Erasing the club's enormous debts, keeping their sharpest talents and even being a contender to sign the likes of Erling Haaland in the summer will all rely on Xavi's side finishing in the top four.
It is why any romantic ideas about style and youth have been tempered by a more pragmatic edge, the kind that persuaded Xavi and Joan Laporta to re-sign a 38-year-old Dani Alves, add the physicality of Adama Traore and bring Pierre-Emerick Aubameyang in from the cold.
Aubameyang could make his debut on Sunday, although given the 32-year-old's last game for Arsenal came on December 6, he might be more likely to start on the bench.
Atletico's problem has been conceding goals rather than scoring them, the collapse of their usually dependable defence the central reason for the crumbling defence of their title. Already, they have conceded 26 goals, one more than they let in all last season.
Four defeats in a row in December not only ended any hopes they had of catching Real Madrid but raised doubts about Atletico's ability to recover and even Diego Simeone’s position as coach.
Yet Atletico face Barcelona on the back of their most rousing victory in months, a comeback from 2-0 down to beat Valencia 3-2 at the Wanda Metropolitano prompting a chorus of pledges about the beginnings of a revival.
Coach Diego Simeone said afterwards he needs to "individualise" the players that engineered the fightback and it remains to be seen how Luis Suarez features from now on, with questions lingering about the sacrifices needed to ensure the Uruguayan succeeds.
Suarez will certainly need no extra motivation on his second return to Camp Nou.
Sevilla can move to within a point of Real Madrid by beating Osasuna on Saturday before Madrid play at home to Granada on Sunday. Real Betis, in third, host Villarreal, in seventh.
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