Joao Felix will not be included in Atletico Madrid's squad to face Liverpool in the Champions League after missing training on Monday.
Felix sustained a muscle injury during Atletico's 0-0 draw at home to Leganes on January 26, which has seen him miss the club's last three fixtures.
The Portuguese starlet was unavailable when Diego Simeone's side lost 1-0 away to Real Madrid on February 1, and when they beat Granada by the same scoreline seven days later.
He was also left out of Atletico's 2-2 draw against Valencia at Mestalla on Friday, but was in line for a return to full training ahead of this week's Champions League showdown against Liverpool.
Goal has learned that Felix is close to making a full recovery from injury, but he has been struck down with pharyngotonsillitis, which is why he will not be involved at Wanda Metropolitano.
Hector Herrera will also be missing through illness, with Kieran Trippier the only other notable absentee for Atletico as he continues his rehabilitation after groin surgery.
Felix completed a €126 million (£113m/$147m) move to Atletico from Benfica in the summer of 2019, becoming the most expensive signing in the club's history.
The 20-year-old made a bright start to life in La Liga, and scooped the coveted Golden Boy award back in November, but he has since struggled for form and fitness.
Felix has netted four goals in 23 appearances across all competitions for Atletico in total, with the general consensus among supporters and experts being that he has yet to live up to his full potential.
He will hope to be back in contention for a place in Simeone's line up when Atletico travel to Anfield for the second leg of their tie with Liverpool on March 11.
Felix recently described the Reds as the "most difficult team" left in the Champions League, and the current holders are favourites to progress against an Atletico side which appears to be in the middle of a transitional phase.
Liverpool boss Jurgen Klopp is expecting a tough examination, however, insisting injury problems have hampered Simeone's preparations in recent weeks.
"If somebody can play for a result, it's Atletico. Mr Simeone, who I respect a lot, he tries everything," the German head coach told a press conference.
Atletico will turn their attention back to La Liga after their latest European outing, with Villarreal set to arrive at the Wanda on Sunday.