Abdoulaye Doucoure will miss Watford's FA Cup trip to Newcastle, and may also be absent for his side's Premier League clash against Tottenham.
Doucoure's future has been a constant thread of transfer speculation this month with both Paris St Germain and Arsenal said to be interested in the midfielder.
The Frenchman, 26, was a late withdrawal for Watford's stalemate against Burnley last weekend following a reported knee problem, and he will not feature in the fourth round of the FA Cup on Saturday.
"Last week when I spoke with the medical staff, they said that maybe in one or two days Doucoure could be available, but now we need to wait and give him more time," said Javi Gracia, the Watford manager.
"In the next two or three days he will be out of the team.
"He has a little problem with his right knee and needs more time to recover. I think he will be available in one week, but we will see."
Asked if Doucoure is unlikely to feature for Watford's league match at Wembley, a day before the transfer window closes, Gracia replied: "I don't know because it depends on his evolution."
Doucoure has starred under Gracia this season, helping propel Watford to an impressive seventh in the Premier League.
But his impressive performances have alerted a host of top-level clubs, while Doucoure has also admitted he is keen to leave Vicarage Road in pursuit of playing in the Champions League.
Watford however, are confident they will be able to stave off interest until at least the end of the season, with Gracia, who earlier this week celebrated his one-year anniversary in charge, urging the midfielder to help take the club on to another level.
Gracia added: "If we can find a good balance, and if we are able to create something with stability, then I think we can take a step forward, and with players such as Doucoure and others we can do that.
"I don't speak with him about next season or about the possibilities he has to change club, or the news that is constantly around him.
"The only time I speak with him is to try and improve different things about his game.
"I listen to a lot of news about him, but in this moment he is here, training, and focused on trying to recover. I am sure he is only thinking about the next game.
"I think he is happy, but this a question is for him."
Craig Cathcart and Will Hughes are both available for the trip to St James' Park, but Kiko Femenia misses out with a hamstring issue.