Atletico Madrid midfielder Thomas Partey has suffered a thigh strain, the Liga club has confirmed.
Ghanaian Partey has broken into the Atletico first team this season having previously spent loan spells at Mallorca and Almeria.
He has made 13 appearances in 2015-16 and scored two goals, including the winner in Atletico's 1-0 victory over Levante last month.
A statement on Atletico's website confirmed: "The midfielder Thomas Teye Partey was unable to complete the morning's [Tuesday] training session and retired before it was over.
"After undergoing a first examination in Majadahonda's FREMAP Clinic, the medical report of Atletico's midfielder indicates that he suffers a grade I injury of the vastus medialis muscle in the right thigh."
Atletico visit Getafe in La Liga on Sunday.