Francis Coquelin will miss the rest of the season after the Valencia midfielder tore his Achilles during training.
Coquelin will require surgery on his right leg having sustained the injury during Friday's session, the club confirmed.
"The player will be operated upon in the coming hours," Valencia said in a brief statement.
Former club Arsenal offered support to Coquelin, posting on Twitter: "We're thinking of you, Francis."
We’re thinking of you, Francis March 16, 2018
Coquelin has made nine LaLiga appearances since joining Valencia from Arsenal in the January transfer window.
Valencia are fourth in the table, 11 points clear of Sevilla in the race for Champions League qualification.
‘After Manchester City’s recent form, maybe they’re the underdogs against Manchester United!’ Former Red Devils defender on this weekend’s derby
‘Arteta, Alonso, Emery, me… none of us were physical players – we needed the understanding of the game. That probably helped us move into management’: Premier League boss reveals reasons for natural career progression
