Manchester United forward Alexis Sanchez is expected to be out for at least a month with a knee injury but there are fears he could spend as long as eight weeks on the sidelines, sources have told ESPN FC.
The Chile international damaged knee ligaments during the 3-2 win over Southampton on Saturday and was limping heavily as he left Old Trafford.
Initial scans on Sunday showed the 30-year-old will need at least a month to recover, ruling him out of the Champions League clash with Paris Saint-Germain on Wednesday and the trip to Arsenal on Sunday.
However, there are concerns he could be ruled out for as long as two months, raising the prospect that he may not play for United again this season.
United play their penultimate Premier League game against Huddersfield on May 4 before a home game against Cardiff on the final day of the campaign on May 12. The FA Cup final is scheduled for May 18.
With caretaker manager Ole Gunnar Solskjaer already dealing with a host of injuries, Sanchez would likely have started against PSG on Wednesday and at the Emirates four days later.
His absence means Solskjaer could be without as many as 10 senior players in Paris.
As well as Sanchez, Ander Herrera, Nemanja Matic, Jesse Lingard, Juan Mata, Anthony Martial, Matteo Darmian, Phil Jones and Antonio Valencia are injured. Paul Pogba is suspended after his red card during the 2-0 first leg defeat at Old Trafford.
Meanwhile, Chile boss Reinaldo Rueda has said he is very concerned with Sanchez's form -- with the ex-Arsenal man contributing just one league goal all season.
"For sure it's very worrying," Rueda said as reported in La Tercera newspaper. "These are situations that happen in football.
"We hope he overcomes this very quickly because he has all the quality, a track record, experience and quality to assert himself. I hope we can enjoy the Alexis we all knew at again."
Chile take on Mexico on March 23 at San Diego's SDCCU Stadium before facing the U.S. four days later in Houston and Sanchez was expected to be called up had he been available.
Last summer was Sanchez's first without international duty since 2013, having played in the 2014 World Cup, back-to-back editions of the Copa America and the 2017 Confederations Cup -- reaching the final of the latter three.
ESPN FC's Spain correspondent Adriana Garcia contributed to this report