Sunderland striker Kenwyne Jones will undergo a knee operation on Monday, manager Roy Keane revealed after his side's 1-0 defeat to Ajax.
The Trinidad and Tobago forward suffered knee ligament damage on international duty against England in June.
And Keane confirmed that he will go under the knife tomorrow to determine the seriousness of the injury.
'Kenwyne's going in tomorrow for an operation and we will know in 24 hours of the exact damage so fingers crossed,' Keane said.
'We'll know one way or another tomorrow so I'll be saying a few prayers tonight.'
Kieran Richardson is less of a concern for Keane, with the former Manchester United winger's absence for today's match merely a precaution.
'Kieran just had a stiff back the last couple of days,' Keane explained.
'There was no point risking him today. I'd be very surprised if he wasn't on the flight to Ireland with us on Wednesday.'
The Black Cats created the bulk of the opportunities against Marco van Basten's team at the Stadium of Light, but went down to Klaas Jan Huntelaar's strike nine minutes after half-time.
Daryl Murphy skimmed the outside of the post just before the interval and El-Hadji Diouf brought a fine save out of Maarten Stekelenburg with a late free-kick, but the hosts were unable to find the net.
Sunderland have had a busy summer in the transfer market, bringing in the likes of Tottenham trio Pascal Chimbonda, Teemu Tainio and Steed Malbranque as well as Diouf from Bolton.
But Keane insists he has spent the last few days focusing on this match - which was staged as part of the celebrations to mark the 35th anniversary of the victorious 1973 FA Cup run - rather than looking for new players to further boost his squad.
'The last few days we all had to switch off,' Keane said.
'We had this game coming up and sometimes have to prioritise, focus on that. But I'm sure tomorrow we'll be back on that roundabout with speculation of who's going where.
'I've said for the last week or two we're hopeful of two or three players coming on board.
'We have two or three weeks to play with but don't want to get backed into a corner at the end of August.'
Keane is satisfied with his current squad, but reiterated he would like three new players before the Barclays Premier League season kicks off against Liverpool in under a fortnight.
'We saw today a lot of good stuff,' he added.
'I was generally pleased with the game today. But we probably need three players.
'Even at the end of last season I thought we needed another top striker at the football club.'