Gary Harkins has become St Mirren's first signing ahead of the new season after agreeing a two-year deal.
Harkins has put pen to paper on a contract until at least the summer of 2015, with the option of a further year.
The 28-year-old, who started his career with Blackburn Rovers, had been linked to numerous SPL clubs following his departure from Dundee at the end of last season.
Harkins originally played for Dundee from 2009 to the summer of 2011 before moving to Kilmarnock.
The midfielder, who has also enjoyed spells with Huddersfield, Bury, Blackpool, Grimsby Town and Partick Thistle, returned to Dens Park last January.
The 34-year-old midfielder will officially join the Dons when his current contract with Sheffield United expires.
Manager Derek McInnes made Dundee United midfielder Willo Flood his first summer signing last week on a similar pre-contract agreement.
McInnes played alongside Robson at Tannadice and he told RedWeb: "Barry is a player I know well and having been a team-mate of his I can see the same hunger and determination within him as he had when I played alongside him.
"It's clear to see he has retained a high level of performance.
"Both Tony (Docherty, assistant) and I have watched him recently and have only had good reports about his performances for Sheffield United.
"We still feel he has that winning mentality and is someone who can bring some real quality to the team.
"We're delighted to have him on board and as a local boy I'm sure he is looking forward to playing for his hometown team."
Inverurie-born Robson, who has also played for Inverness, Celtic, Middlesbrough and Vancouver Whitecaps while gaining 17 caps for Scotland, said: "I think it's something I have always wanted to do, it's something my family have always wanted me to do and I am very privileged to be able to join now.
"I know how big a club this is, I know how good a club it is and it's always a club I wanted to play for and I am just glad I am getting the opportunity to do that."
