Manchester United interim manager Ruud van Nistelrooy is unsure if he will still be at the club beyond the next two games.
The Dutchman was put in charge following the sacking of compatriot Erik ten Hag in October.
Van Nistelrooy, who was part of Ten Hag's coaching staff, will oversee United's Europa League meeting with PAOK on Thursday and the Premier League clash with Leicester City on Sunday before Sporting's Ruben Amorim becomes permanent manager on Monday 11 November.
"It's difficult to comment on that now, I am waiting for conversations to take place," said former United striker Van Nistelrooy on his future.
"In the meantime the most important thing is getting the work done on a daily basis and in the game tomorrow in Europe. I have to say that I feel the responsibility to do well over the next week and that is my job. I am focused on that.
"I welcome Ruben [Amorim], I am happy to help him and that is the situation at the moment."
Under Van Nistelrooy United beat Leicester 5-2 to reach the EFL Cup quarter-finals and drew 1-1 with Chelsea in the Premier League.
Before Thursday's meeting with the Greek side, £52m summer signing Leny Yoro participated in full training. Having fractured his foot in August, the French defender, 18, has yet to make his competitive debut for the club.
Midfielders Christian Eriksen, Mason Mount and Antony were also in training on Wednesday following injury absences, but defenders Harry Maguire and Luke Shaw remain unavailable.