Julio Arca has signed a new two-year deal with Championship side Middlesbrough.
The 30-year-old left the club at the end of last season after his contract expired, but had been training with the North East team over the summer.
"Julio was outstanding last season and I'm delighted he has decided to extend his career at Boro," manager Tony Mowbray told the club's official website.
"He is popular with the fans and in the dressing room; he is a player I value for the skill and experience he can bring to our team."
The Argentine joined the Riverside outfit from Sunderland in 2006 for £1.75m.