Southampton midfielder Morgan Schneiderlin will miss the rest of the season because of a knee injury, manager Ronald Koeman has confirmed, though the manager sees no reason to believe he has played his last game for the club.
The Frenchman suffered the problem during the 2-2 draw against Tottenham last weekend, with scans revealing the problem was serious enough to sideline him for up to a month.
Koeman said at a press conference: "Morgan will be out until the end of the season, for four or five weeks."
Southampton head to relegation-battlers Sunderland on Saturday looking to maintain hope of European qualification, currently in seventh place but only a point behind both Spurs and Liverpool who occupy the two places which currently earn Europa League football.
Schneiderlin had played a central role in Saints' promising campaign, which had seen them in the Champions League places in the early stages of the season.
The 25-year-old's performances have seen him linked with a summer move away from St Mary's Stadium, with the likes of Tottenham and Arsenal reported targets, although the club insists he is not for sale.
"He is a key player, so it is disappointing," said Koeman. "It is the ligaments of his left knee and that is a shame because he's out for the last part of the season."
Despite the prognosis, Schneiderlin remains determined to play again ahead of Saints' final match at Manchester City on May 24.
Sad about my injury .. I am not giving up on coming back before the end of the season ! Thanks to everyone for their support !
- Morgan Schneiderlin (@SchneiderlinMo4) April 30, 2015
It has been suggested Schneiderlin wants to secure a summer move to a Champions League club.
Koeman added: "He is happy [here], but it is up to the player. "We like to keep everybody but we know sometimes it's difficult. But there isn't any serious bid for the player."
The Southampton manager also confirmed midfielder Dusan Tadic would miss the trip to the north east.
Koeman said: "He is struggling with some groin problems for a long time and we decide now to put him out of the team because he has to recover and be 100 percent and, if not, he will struggle next season and we don't want that."
Victor Wanyama will be available again following suspension at the Stadium of Light, so Toby Alderweireld could drop back into defence.
Southampton thumped Sunderland 8-0 at St Mary's in October. Koeman, though, is not expecting another walk in the park against a team fighting for survival under new head coach Dick Advocaat.
"We had unbelievable help from the players of Sunderland. It was so strange. We didn't play really well," he said. "We scored great goals, but the game of this Saturday will be totally different.
"Sunderland have two home games and they need two wins. That means a lot of pressure and we have to prepare for that."