Atletico Madrid coach Diego Simeone has backed youngster Lucas Hernandez to impress at Osasuna on Sunday in the absence of injured left-back Filipe Luis.
Luis, who had played every minute of the season, injured a thigh muscle in the midweek Champions League win over PSV Eindhoven and Simeone has no specialist replacement in his squad.
The coach told a news conference that Lucas, 20 -- normally a centre-back -- would deputise, adding: "I always say we have players with different characteristics who can strengthen the team in different ways.
"He has played there, and played there well. It will be Lucas and we will see how he does."
Opponents Osasuna are also in need of points, 19th in the table and with veteran coach Joaquin Caparros in charge of his first home game since taking over the role.
"Tomorrow we will take on a team with a coach I respect a lot," Simeone said. "His teams have always showed the energy he has, and that will feed into the atmosphere.
"It will be a game with a lot of intensity. As always, we will try and take it to a place which suits us better."
Atletico are nine points behind leaders Real Madrid in the La Liga table and have already qualified as group winners for the knockout stages of the Champions League.
They also face a Copa del Rey last 32 first leg game at third tier Guijuelo next week, and Simeone said: "Whoever knows me know that we always play each competition with the same motivation.
"I have always said that the Copa del Rey was a very nice competition, the Champions League is a different feeling.
La Liga, for the clubs, for the fans, means everything. Every Sunday they look to see where they are in the table, it is important whether their team are fifth or seventh."
Atletico's 19-man squad for the game includes 17-year-old Uruguayan forward Nicolas Schiappacasse, who had already impressed at senior level for Argentine club River Plate before joining Atleti in the summer.