Carlo Ancelotti's side dropped points against Valencia and Real Valladolid in disappointing draws last week, meaning Barca and Atletico both now have the league crown in their hands.
Those draws have left Real four points adrift of city rivals and UEFA Champions League final opponents Atletico, who host Malaga this weekend as Barca travel to Elche.
With Diego Simeone's men heading to Camp Nou on the final day, there remains an outside chance for Real to usurp their rivals and claim back the crown they last won in 2012.
Having won the Copa del Rey in April, and with a Lisbon showdown against Atletico to come later this month, Ancelotti refuses to give up on winning a treble.
He said: "Winning La Liga will be very difficult, but it's still mathematically possible. We have to carry on and win our remaining two La Liga games. I'm not concerned about who the favourites are to win the title."
The Real coach is confident of having Cristiano Ronaldo available after the Portugal forward limped off with just nine minutes on the clock in Wednesday's 1-1 draw against Valladolid.
"He wasn't in pain and wasn't complaining of a muscle sprain," Ancelotti said.
If Ronaldo does miss out, Real may turn to a new goalscoring hero to find the net after Sergio Ramos made it five in four matches with the opener in midweek.
The defender, perhaps more famed for clocking up cards than goals, marked his 400th appearance for the club with his 36th Liga goal for the Bernabeu outfit.
Celta, who have won three in a row, provided spirited opposition for more than an hour in January's reverse fixture before Karim Benzema broke their resistance and Ronaldo added two more in a 3-0 win for the hosts.
But it has been a hugely improved campaign for Celta, who triumphed in their final two games last term to finish just one point above the relegation zone.
Luis Enrique's side look set for a top-half finish and they have been in fine form in front of goal lately, scoring 12 times in their past four outings.
The visitors will be without defender Pepe, who has a calf injury, while Celta could stick with Sergio Alvarez in goal after he made his first appearance of the season in place of Yoel for the 2-0 win at Osasuna.
