After leading the league for over half the season, Barcelona suddenly find themselves without any margin for error if they want to avoid dropping out of the title race.
Martino will likely rest Gerard Piqué to ensure he has his defender available for next weekend's Clásico. Piqué is one yellow card away from a mandatory suspension, and risking him picking up that card against Osasuna would be a bad idea. With their Champions League Round of 16 tie complete, Martino can focus on the league for a week but he can ill afford to see his side slip-up again.
After wins for Madrid and Atlético on Saturday, Barca must win to keep pace. It's as simple as that.
Osasuna are precariously perched three points clear of the drop zone in 15th place. With nearly everyone behind them suddenly starting to get points, there's work to be done for the Rojillos if they want to avoid life in Second Division.
Barcelona injuries and suspensions
Out: Jonathan dos Santos (knee), Isaac Cuenca (hamstring).
Osasuna injuries and suspensions
Out: Sisi (knee), Miguel de las Cuevas (toe). In Doubt: Marc Bertran (hamstring).
Osasuna: Andrés, Oier, Jordan Lotiès, Damià, Lolo, Francisco Silva, Álvaro Cejudo, Roberto Torres, Emiliano Armenteros, Oriol Riera
Match Date/Time: 4 p.m. local, 11 a.m. ET
Venue: Camp Nou, Barcelona, Spain
TV: beIN Sports USA, beIN Sports en Español (U.S.), Sky Sports 2 (U.K.), Canal+ Liga (Spain)
Online: beIN Sports Play (U.S.), beIN Sports Play (Canada), Gol Stadium (Spain)