The central defender, the second most-capped player in Ecuador's history at the time, had previously played in Europe with Eredivise side Vitesse Arnhem.
Espinoza, who featured for his country at both the 2002 and 2006 World Cup finals, won two league titles with LDU Quito and has also captained Cruzeiro.
The player's nickname is La Sombra, or "The Shadow".
The defender had long been tracked by a number of clubs and it was Cardiff's failure to reach the top flight which prompted their decision to cash in.
He began his career with Wycombe Wanderers, though he was also on the books of Portsmouth and Bournemouth as a youngster, making 159 appearances for the Chairboys before moving to Ninian Park for £275,000 in the summer of 2006.
Johnson was Cardiff's Player of the Year in 2007-08 as they lost to Portsmouth in the final of the FA Cup.
The player became one of the finest performers in the Championship in 2008-09, named in the divisional team of the year and again being named the Bluebirds' Player of the Year.
That led to interest from the Premier League and he moved to Birmingham after 119 appearances and 12 goals for Cardiff.
The striker had begun his career at El Nacional, where he impressed with his power and goalscoring ability.
The son of one of Ecuador's all time top scoring players, Ermen Benítez, he was a member of the Ecuador national team at the 2006 FIFA World Cup and his speed, elusiveness, and skill with the ball made him one of the standout performers.
Scoring nearly a goal every other game for Ecuador, Benitez has forged himself a decent reputation at international level and he made an unexpected move to Santos Laguna of the Primera División de México and quickly established himself as one of the best foreign strikers in the league.
Benitez starred in the Mexican Clausura in 2008, where he led the team to the title and was voted the best player of the season; and in June, 2009, he signed a three-year contract for Birmingham.
