Carlo Ancelotti's men have yet to concede a goal in 2014 but they are going up against a side that has yet to lose a single game on home soil in La Liga this season.
Real Madrid's 20-match unbeaten streak will come under threat when it travels to fourth-placed Athletic Bilbao on Sunday.
Carlo Ancelotti's side has a chance to overhaul Barcelona after the league leader lost to Valencia on Saturday.
The Santiago Bernabeu side has been in exceptional form recently, with its last defeat in any competition coming against Barca at Camp Nou on Oct. 26.
It has won 17 of 20 matches since then, a run that has it them reach the Copa del Rey semifinals and the last 16 of the Champions League.
Forwards Cristiano Ronaldo and Karim Benzema have helped Madrid become the most prolific side in the Spanish top flight, with 60 goals this term.
Welshman Gareth Bale has also chipped in with eight goals from 14 league appearances, but he could miss the trip to Bilbao with a leg injury.
Los Blancos, though, have won all eight of their matches so far this year without conceding a goal, making this their best January ever.
However, they face an Athletic outfit with an imposing home record, with Ernesto Valverde's side yet to lose a match at San Mames in La Liga this season.
And although they it in the Copa del Rey to Atletico Madrid on Wednesday, bowing out 3-1 on aggregate, it has won its last three league matches, scoring freely in the process.
A 6-1 thrashing of Almeria on Jan. 11 was followed by 4-2 and 5-1 successes against Real Valladolid and Osasuna, respectively.
History is on Madrid's side, though, with the capital club having won the last eight meetings between the two sides in comfortable fashion, scoring at least three goals in all of its triumphs.
An Isco double helped Real to a 3-1 win in the match earlier this season, while Ronaldo also scored in the home triumph.
In terms of team news, center back Raphael Varane is back in training for the visitors following a knee problem, but is yet to return to first-team action.