Martinez's side won the first major trophy in the club's 81-year history in sensational fashion on Saturday as Ben Watson's stoppage-time header clinched a 1-0 win over City at Wembley.
Watching his Wigan underdogs cause the greatest Cup final upset since Wimbledon beat Liverpool in 1988 was the culmination of a remarkable journey for Whelan, who bought the club in 1995 when they were playing in the fourth tier at dilapidated Springfield Park in front of sparse crowds.
Substitute Ben Watson scored a stoppage-time winner for underdogs Wigan in their shock victory over City, who had Pablo Zabaleta sent off.
Ben Watson scored his first English Premier League goal since December 2011 to give Wigan a 1-0 victory over Tottenham at White Hart Lane on Saturday.