Middlesbrough have confirmed that midfielder Julio Arca is training with the club despite his contract expiring at the end of last season.
Manager Tony Mowbray had wanted the Argentine to sign a new deal but an agreement could not be reached.
Arca, 30, has just returned to full fitness after missing the end of last season with a knee injury.
There is no indication that Boro will attempt to reach a new agreement with the former Sunderland player.
Arca began his career with Argentinos Juniors and moved to the Black Cats in 2000 in a £3.5m deal.
He joinedBoro for £1.75m in July 2006 and went on to make 149 appearances, scoring nine goals.