Wigan Athletic have signed Chelsea striker Franco di Santo on a three-year contract for an undisclosed fee, reported to be £2 million.
Di Santo, who spent last season on loan at Blackburn Rovers and after, has struggled to make his mark on the Chelsea first team after joining the club from Chilean side Audax Italiano in 2007.
The Argentina Under-20 international made just 11 appearances for the Blues during the 2008-09 season, but Di Santo was top scorer for Chelsea reserves the previous term.
Di Santo made a promising start following his loan move to Wigan's Lancashire rivals Blackburn during the 2009-10 season but quickly faded into the background at Ewood Park.
He passed a medical at the DW Stadium earlier on Tuesday and will look to make his mark in the Premier League with Wigan.
Martinez added: "Franco is an Under-20 international for Argentina with great Premier League experience having worked at a club with the calibre of players of Chelsea, and also spending a hugely beneficial year on loan at an established club like Blackburn.
"We all feel that Franco can fulfil his potential at our football club and he'll bring a completely different dimension to our squad with his presence, technical ability and hard-work."
Di Santo said: "I am just happy that my future has been sorted out now. I can't wait to start training, meet all my new team-mates and start fighting for my place in the team. Roberto Martinez has big ambitions for the club and he made it clear how much he wanted me to be here.
"When a manager is so positive about you, then it is an easy decision to make."