Middlesbrough defender George Friend, 32, has linked up with former boss Aitor Karanka at Birmingham City.
The left-back said that Karanka was a huge factor in his decision to join him at St Andrew's and the project he has planned out with Blues.
Friend told the club's YouTube channel in his first interview: 'Aitor is a big reason.
'I had a successful time with him at Middlesbrough and I know what he's all about.
'I know that he's looking to build something here and the club has got ambition in that aspect.
'There's a good feel around the place with his appointment. He was keen to bring me in and I'm looking forward to getting going.
'I'm not sure I've been a first signing before at a club but I guess I'll take that honour!'
Boro and Swansea City are keen on former Hull City midfielder Kevin Stewart, 26, who is a free agent.