Bristol City are taking a look at former Middlesbrough defender Matthew Bates.
The 25-year-old is a free agent after rejecting a new deal at Boro and is training with the Robins.
Boss Derek McInnes told the club's official website: "He's left Middlesbrough and is pleased to be training with us.
"Obviously he needs to build his fitness up after his latest injury, and we'll be having a look at him for a week or so."
Bates made over 100 league appearances for Boro, but suffered a number of knee injuries throughout his six years at the club.