Sunderland No2 Eric Black is confident Cristian Riveros will prove his class on Wearside.
Black thinks the former Cruz Azul man - who is due back in the country at the end of the month - can be a hit on Wearside.
"Paulo and Cristian were both fantastic in South Africa," he told safc.com. "I watched all their games and spoke to them after every single game.
"I'm absolutely delighted and was very impressed with both of them.
"I've seen Cristian a couple of times, in Paraguay and also in Bilbao in Spain.
"I liked his energy; he's physical, he gets about the pitch well and he's very competitive. But he can handle the ball too; he's a competent footballer.
"He'll add competition to the midfield and from what I've seen I have no doubt that he can do it in the Premier League."
