Fabian Schar may have played his last game for Newcastle after tearing knee ligaments during Newcastle's win over Southampton.
The Switzerland international, who is out of contract in the summer, will undergo further assessment with a specialist consultant in the coming days but his club have ruled him out for "several months".
Schar says he is targeting a return for the European Championships in June, casting further doubt on the chances of him playing again in the Premier League this campaign.
Difficult to accept. I felt really good on the pitch and the team did well the last few games. Now i will be out for a few months and its gonna be a hard time. But i will try everything to be back on the pitch as soon as possible. And my goal will be to be ready for the euros🙏. pic.twitter.com/6LyooFpCGx— Fabian Lukas Schär (@fabianschaer) February 7, 2021
He said: "Difficult to accept. I felt really good on the pitch and the team did well the last few games.
"Now I will be out for a few months and it's gonna be a hard time. But I will try everything to be back on the pitch as soon as possible. And my goal will be to be ready for the Euros."
Schar was stretchered off in the 75th minute, which forced the home side down to 10 men having already used their three substitutes, having jarred his right knee attempting to strike a rebound from his own free-kick.
His team-mates Callum Wilson and Javier Manquillo were also taken off during the game, as the Magpies held on to win 3-2.
Schar could yet be offered a new contract to stay at St James' Park but he appears unlikely to be able to play his way into contention for another deal, other than for his country come the summer.
Newcastle confirmed in a statement: "The Switzerland international sustained a torn knee ligament in the 75th minute of the match and had to be stretchered from the pitch.
"He will undergo further assessment with a specialist consultant in the coming days before beginning his rehabilitation with the club's medical team.
"Everyone at Newcastle United wishes Fabian a full and speedy recovery."