The new signing was the hero as Argentina beat The Netherlands in the World Cup semi-finals.
The 28-year-old has previously been at the likes of Racing Club in Argentina as well as Dutch side AZ Alkmaar and French outfit AS Monaco on loan.
Now 28-years-old the stopper, who has 62 caps for his nation, arrives with doubts surrounding fellow goalies David De Gea, Victor Valdes and Anders Lindegaard.
Romero is of course well known to Manchester United boss Louis van Gaal, for all the wrong reasons.
He was named man of the match in the World Cup semi-final between Argentina and what was then the current Manchester United coach’s Netherlands side.
He saved penalties from both former Aston Villa defender Ron Vlaar and Galatasaray midfielder Wesley Sneijder as Argentina went on to the final at Holland and Van Gaal’s expense.
Romero went on to concede to Mario Gotze in the final, as Germany were crowned World Champions, but he was fantastic throughout the competition – being named on the three man shortlist for the World Cup Golden Glove with Manuel Neuer and Costa Rica’s Keylor Navas.
Van Gaal will be hoping for similar heroics now he has Romero under his command.