Manchester United defender Luke Shaw was absent from his side's 3-0 win at Nottingham Forest in the Carabao Cup due to illness.
United emerged from the first leg of their semi final with a decisive lead to take into the second leg at home.
Shaw, who has been in good form since the World Cup break, is unwell not injured according to manager Erik ten Hag.
Difficult to say how that develops," ten Hag told reporters post-game.
We have to wait to see how that develops in hours and days."
United face Reading in the FA Cup this weekend and then play the second leg against Forest at home.