The winger has made four appearances so far and scored his first goal for the Reds to clinch a 2-2 draw at Brighton and Hove Albion last month.
The Paraguayan star was wanted by a number of clubs around Europe including many in the Premier League during the summer.
Ribonetto, who worked with Sosa at his former club, says the 25-year-old had a major ambition to play in England’s top division and spoke to Paraguayan media outlet Versus about how he was eager to sign for a Premier League side.
“He was convinced that he was going to play in the Premier League. He told me, 'Saturday, Tino, turn on the TV, I'm going to be there, I'm going to play in the Premier League'. He was very convinced.”
Sosa has made his dream come true and has already started life in the Premier League with a bang as Forest look to build on his potential shown with Talleres.