Manchester United defensive duo Lisandro Martínez and Víctor Lindelof will be out of action for a month.
The double blow is another hard setback for Erik ten Hagwho has had to deal with huge injury problems all season.
And particularly to Martínez, who United They are desperate to strengthen their defense but he simply cannot stay fit as he has only recently returned to training.
The Argentine international had just returned from injury when he suffered a calf strain in training and now faces another month on the sidelines.
The World Cup winner had spent seven weeks in the physiotherapy room and Ten Hag hoped to have him fit enough to begin the trip to Chelsea on Thursday night, live on talkSPORT 2.
Joining Martinez on the sidelines is Lindelof, who has also had a lot of injury problems this season.
The Swedish international suffered a hamstring injury Brentford They drew 1-1 on Saturday and will also be out of action for a month.
Martinez replaced the 29-year-old with 20 minutes remaining against the Bees.
In a statement on their website, United wrote: “Manchester United centre-backs Victor Lindelof and Lisandro Martínez will be out of action for at least a month due to muscle injuries.
“Swedish captain Lindelof was taken off during the second half of last Saturday's Premier League match against Brentford with a hamstring problem.
“Víctor was replaced by Martínez in the 69th minute, when the Argentine international made his first appearance since early February.
“Unfortunately, Licha suffered a calf strain during training and will not be available for the upcoming matches.”
Ten Hag are already without left backs Luke Shaw and Tyrell Malacia and face another makeshift defense on Thursday night.
With a month-long absence for both Martínez and Lindelof already underway, it remains to be seen if they will be fit enough for the end of the season.
The pair will miss five Premier League matches, including against Chelsea, as well as United's FA Cup semi-final against Coventry on April 21.
The Red Devils are currently sixth in the Premier League and are 11 points behind fourth place. Aston Villa.