The injuries picked up by Lucas Hernández and Diego Costa have left Atlético Madrid facing the prospect of having just 13 outfield first-teamers available for this weekend's LaLiga match against Levante.
Lucas, Costa taken off injured in Lisbon
The pair were forced off in Thursday's Europa League quarter-final second leg at Sporting CP, which saw Atlético book their place in the last four of the continent's second-tier competition, despite losing 1-0 on the night.
Defender Lucas suffered a facial injury, although the club have confirmed that he has not broken his cheekbone, while striker Costa limped off with a thigh problem.
Atlético, whose 19-man senior group means Simeone is currently forced to draft 'B' team players into every matchday squad, are already without long-term absentee Filipe Luis, who fractured his shinbone in March, while Thomas Partey serves a one-game ban against Los Granotas on Sunday.
Vrsaljko would fill in for Lucas at left-back
If Lucas and Costa are ruled out of the clash at the Wanda, Atleti's available first-team players will be: Jan Oblak, Axel Werner, Juanfran, José María Giménez, Diego Godín, Stefan Savic, Sime Vrsaljko, Ángel Correa, Vitolo, Gabi, Saúl Ñíguez, Koke, Antoine Griezmann, Kevin Gameiro and Fernando Torres.
Having done so in Lisbon, Vrsaljko would be likely to fill in for Lucas at left-back.