Paraguay goalkeeper Justo Villar will undergo a scan on his right leg to discover whether he will play any further part in the World Cup.
The Newell's Old Boys custodian suffered a heartbreaking start to the tournament, conceding an early goal in the opening Group B defeat against England on Saturday, before tearing a muscle on the inside of his right leg after only seven minutes.
Paraguay's team doctor Osvaldo Pangrazio confirmed Villar will miss the remaining group games against Sweden and Trinidad & Tobago and, depending on the scan results, could sit out the remainder of the competition.
Pangrazio said: 'We'll do a diagnosis to confirm the seriousness of this injury, but anyway I think he is already out of the upcoming matches (against Sweden and Trinidad & Tobago).
'If the tear is less than one centimetre, he will be able to play in the last 16 (June 24 or 25) or quarter-finals (June 30 or July 1).
'It's very difficult to recover in such a short time.'
Pangrazio added this is the first time Villar has suffered such an injury and that the muscle was healthy.
The doctor also revealed Diego Toledo's thigh injury could keep him out of Thursday's clash with Sweden in Berlin and warned: 'We must be very careful, because it's a muscular injury.'
If Toledo misses out, Jorge Nunez will take his place at left-back.
Pangrazio admitted Carlos Humberto Paredes, Carlos Gamarra and Roberto Acuna were also recovering from minor knocks, but that striker Roque Santa Cruz - who was a doubt for the England match - felt no reaction to the right knee that had been troubling him.