Arismendi, nicknamed 'The Destroyer', is an extremely highly rated defensive midfielder courted by some of Europe's biggest clubs this summer but turned them all down to sign for the Potters as he looked for a club that was both in England and where he would be a first team regular.
The Uruguayan has two caps for his country and for a fee of £5m many believe the Potters have got a bargain for a player that they can build the team around.
Arismendi helped his former club Nacional to the semi finals of the Copa Liberadores, a massive achievement for a side with such limited resources, after they won the league last season with Arismendi judged to be one of the key men in both successes.