Riveros Ready For Wearside
Steve Bruce has admitted it has been frustrating as Sunderland have had to wait for Riveros to join up with the squad in England.
Bruce joked: 'We are still looking for Riveros to come through the door. We don't know where the hell his passport is - somewhere between Paraguay and New York!
'But we expect him to be in by Wednesday or Thursday.'
Riveros, 28, has been training in South America since he joined Sunderland on a bosman transfer in June.
Bruce is looking forward to seeing the midfielder in action and hopes to include him with the first team as soon as he can.
Bruce added: 'They need to get their passport stamped and visa changed, and with having the World Cup in the middle of it didn't help - especially with them getting to the quarter final. If they'd got knocked out in the early rounds, it would have helped!'